Question 1

What is the hardness testing principle for your UH200 Ultrasonic Contact Impedance hardness tester?

Accepted Answer

Using a Vickers indenter and ultrasonic technology, the hardness tester is first calibrated using a sample of known hardness. The working principle, in short, is the use of an oscillating rod inside your hardness probe. When you apply force to the indenter on your sample, you change the frequency of the oscillating rod. By doing this, and having calibrated using the sample of known hardness, the ultrasonic hardness tester can compare and determine your material hardness.

Question 2

What hardness testing scale will the portable UItrasonic Hardness tester read?

Accepted Answer

While the UCI tester does use a Vickers indenter, the instrument will provide values in Vickers, Brinell and Rockwell (HRC and HRB). With the UH200 UCI portable hardness tester, you can set and forget about constantly requiring to change your favorite scale.

Question 3

What are the common uses for the UH200 ultrasonic portable hardness testing instrument?

Accepted Answer

With a variety of hardness probes requiring different forces, the ultrasonic contact impedance hardness testing system is prepared to test on applications as delicate as metal foil and reach as far as finished work pieces, electroplating layers, carburizing layers, nitriding layers and other heat treat hardness testing requirements.

Question 4

What accessories are available for the UH200 portable Rockwell ultrasonic hardness tester?

Accepted Answer

The main accessories available for the UH200 ultrasonic hardness testing instrument include a variety of probes. There are manual as well as automatic motorized probes. Probes for hard to reach areas with long needle point indenters and shorter probes for getting into tight spaces. We also have a variety of forces available for our probes which require different loading forces before a measurement is ready. This is especially useful when you are looking to UCI test more fragile specimens.

Question 5

Are there any Telebrineller Steel test bars included with the standard configuration of the Telebrineller hardness testing system?

Accepted Answer

Yes! There are five bars included of your selected hardness. Simply inform us of your desired hardness values upon ordering your main unit and we will be happy to include them with your purchase!

Question 6

How do I calibrate my telebrineller hardness tester?

Accepted Answer

We strongly recommend to purchase our calibration disc for checking the calibration of your microscope. Your telebrineller hardness testing system does not require calibration itself.

Question 7

What spare parts should I purchase for telebrineller hardness testing?

Accepted Answer

If you plan to perform a lot of tests, we strongly recommend purchasing additional impression balls. Over time, the ball can deform and cause out of round impressions. The calibration disc for checking your microscope is also a key component to making sure your telebrineller Brinell portable hardness tester is functioning accurately.

Question 8

Can I use the telebrineller for the testing of fillet welds?

Accepted Answer

Absolutely! If you accompany your portable Brinell tester with the halteman filletester, you will be able to test fillet welds and other hard to reach areas.

Question 9

What is the accuracy of the telebrineller portable brinell hardness tester?

Accepted Answer

The standard telebrineller test bars are guaranteed to have a uniform hardness within plus or minus 2% of the BHN etched on the end of the bar. By following the National Institute of Standards (NIST), we ensure every brinell steel test bar is prepared to provide only the most accurate results on your portable brinell hardness testing.

Question 10

What is the standard practice when using the portable hardness brinell tester?

Accepted Answer

The use of the telebrineller hardness testing system is quite simple. The principle is to use a test bar of known hardness that is plus or minus 15% of your expected hardness value. The test bar is inserted into the cost effective portable hardness tester and the unit is placed on your specimen. Below the test bar sits an impression ball. The operator will strike the anvil with a hammer to indent both the specimen and the test bar. Using the microscope, you can then measure the diameter of indentation left on your specimen and compare it on the included chart to find your BHN brinell hardness value.

Question 11

How often do I need to replace the telebrineller steel test bars?

Accepted Answer

Each certified test bar typically allows 20 test indentations per side &ndash; giving you a total of 80 tests per bar. The spring loaded mechanism will adjust your test bar to a new location after you perform a test. This ensures your cheap telebrineller hardness tester is ready for its next test right away!

Question 12

How does the UH200 Ultrasonic Hardness Tester compare to the Mic 10 system?

Accepted Answer

Krautkramer Mic 10 tester is a German engineered unit. They have an overall good market presence for over 10 years. Based on our most recent competitive research, the technology is somewhat out of date with the primary design being virtually identical to what it was when first manufactured. UH200 offers a unit that provides your facility with a machine offering the same functions. The difference is our improved ease of use and accuracy. The major difference, however is the price. Request quote today to learn more.

Question 13

Is it possible to do multiple calibrations on a single NIST traceable Vickers test block?

Accepted Answer

It is possible to have a test block with multiple force calibrations. In order to calibrate a test block according to ASTM E92, 5 sets of 5 indentations are required (25 total). Therefore should you require 2 calibrations, the unit will have 50 micro indentations before being used for testing. This of course will still leave plenty of room for your other tests. The test blocks are calibrated according to ASTM E92. NextGen works in partnership with an ISO 17025 companies who certify the test blocks. Each unit comes with a certificate of calibration.

Question 14

Does the Ultrasonic Hardness Tester System offer Brinell readings?

Accepted Answer

The UH200 ultrasonic tester comes standard with a Brinell scale which it automatically converts and displays hardness readings on the unit. Simply set the scale to HBW and the unit will take care of the rest.

Question 15

What is the Vickers Hardness Range that can be accommodated by the UHT?

Accepted Answer

NextGen&rsquo;s Ultrasonic hardness tester offers HV scale range of 8-1500 HV for the Main Line model and 200-999 for the Economical Line model.

Question 16

What Conversion Scales are Available for the Ultrasonic Hardness System?

Accepted Answer

The Ultrasonic tester can get the HV scale directly, and support conversions for the following scales and ranges: HBW (85-650) / HRA (61-85.6) /HRB (41-100) /HRC (20-70)/HS (34.2-97.3), etc.

Question 17

What is the Operating Temperature for he Ultrasonic Hardness Tester?

Accepted Answer

The UH200 model offers operating temperature between -10*C &ndash; +50*C. Additionally, the unit can be stored within temperature ranges of -30*C &ndash; +60*C.

Question 18

Do you carry any hardness test bars in stock?

Accepted Answer

At all times NextGen has a certain stock of hardness test blocks readily available to meet your needs. Simply submit you quote request or contact our qualified representatives to help check the stock for you. Should we be out, our team will be happy to provide you our best lead times.

Question 19

What is the typical lead time for your NIST traceable Vickers hardness test blocks?

Accepted Answer

The typical lead time for the NIST traceable Vickers hardness test blocks is 2-4 weeks. We always try our very best to bring the lead time down as much as possible, because we understand that your needs may be urgent. Expedited options are available at an additional cost, feel free to contact us today to inquire.

Question 20

Do you ship hardness test bars internationally?

Accepted Answer

Absolute, we would be happy to assist you with international shipments. Please note that all international shipments of hardness test blocks are subject to 100% advanced payment terms for both the inventory and shipping charges. Contact us today to learn more.

Question 21

Can I expedite my order of certified test blocks?

Accepted Answer

Expedited orders for certified test blocks are an option for an extra fee. Please contact us today to learn the difference in price based on your specific test block requirements.

Question 22

Do all test blocks come with certificates of calibration?

Accepted Answer

Yes, without an exception, all of NextGen&rsquo;s hardness test blocks come standard with a certificate of calibration. Soft copies can be requested for your reference.

Question 23

What is the minimum material thickness for the UCI &ndash; Ultrasonic Contact Impedance Hardness Testing Method according to ASTM A1038?

Accepted Answer

When performing the Ultrasonic Hardness Test while testing thinner materials, in the 2-5mm range, an excellent solution is to stack the specimens to increase thickness. The goal is to bring the thickness over 5mm (0.2&Prime;). This will drastically improve your accuracy. The same concept applies to the specimen&rsquo;s weight. In order to optimize accuracy, the weight of the specimen should be over 300g. Should your specimens be lighten than 300g, a stacking option may be highly beneficial to meet this weight requirement. This too will improve your testing result accuracy.

Question 24

What are your Ultrasonic hardness testing recommendations for thin specimens of harder materials like cutting wheels and knives?

Accepted Answer

When performing UCI testing on harder and thinner materials of around 3mm because knives typically have a very high hardness, a 2mm or 3mm (1/8&Prime;) thickness can be accurately tested directly. For example, gears and knives are typically hardened materials with hardness values in the carbide ranges. Provided the specimens are over 2mm thick, the operator is not required to stack the materials in order to gain accurate reading results. Please refer to the below picture example of an abrasive cutting wheel with a 2 mm thickness tested on our UH200 model.

Question 25

What are the factors that may affect the Ultrasonic hardness reading accuracy?

Accepted Answer

There are a few factors that may affect the reading accuracy. They include thickness, hardness, weight and also surface roughness. Please refer to the below roughness table for reference. Here are the two most important questions we ask our clients to answer to help offer the optimal solution for their UCI needs. #1 What are the hardness ranges of your materials? #2 Would you happen to know the surface roughness of your materials? Contact us today and one of our qualified representatives today to get the help that you need with the right solution for your Ultrasonic hardness testing requirements.

Question 26

Do you offer Vickers hardness test blocks for carbide value ranges of over 850HV?

Accepted Answer

Absolutely, NextGen has the full range of regular and carbide level NIST traceable hardness test block that you need. Regular Vickers test block ranges are up to 850HV and the carbide ranges are 850HV and over. Whether you need 1200HV, 1650HV or more, we have you covered. Request quote today to get the pricing for hardness test block that best meets your testing requirements. Do you offer expedited lead times for your NIST certified test blocks? Expedited lead times are always an option. The prices expedited lead time will depend on our production stage. We recommend you contact us to confirm the absolute best lead time and associated cost that we can offer. It is worth noting that our standard lead times are faster than most of our competitors on the market. If waiting is an option, we will do our very best to impress you.

Question 27

What Are the Standard Metallography Consumables Recommendations for a Polishing and Grinding Composite Materials?

Accepted Answer

Historically, there are two methods of polishing and grinding process for composite materials: Traditional Method: Grinding process &ndash; 320, 600, 800, and 1200 grits Polishing process &ndash; 6 um (polishing cloth), 3um (polishing cloth), 1um (polishing cloth) along with aluminum oxide powder or diamond suspension fluid Contemporary Method: Grinding process &ndash; 240 SIC paper Polishing process &ndash; 9um (diamond platen &ndash; Golden), 6um (polishing cloth), 1um (polishing cloth) with diamond suspension fluid Standard Engineering Recommendations: The below process offers a standard recommendation for polishing and grinding needs. This can be adjusted as needed, depending on your materials and surface finish requirements. Contact our qualified consultants to learn more. Here is a cost effective GRINDING: The most cost-effective consumables option for grinding would include a combination of our 12-inch MAGNEPAD Stainless Steel Magnetic Base Plate &ndash; Part #: SSMAG-P12 combined with the following adhesive backed grinding pads. Our recommendation based on your material and relatively smooth starting surface would be to start with: 240 Grit paper &ndash; Part #: SIC-240P12-100 600 Grit paper &ndash; Part #: SIC-600P12-100 1200 Grit paper &ndash; Part #: SIC-1200P12-100 You can always add more grinding paper grits as needed. NOTE: For optimal convenience, you would require one Steel Magnetic Base Plate per grinding paper. This combination will allow you to easily switch out your stainless steel magnetic base plates with grinding paper as needed; while benefiting from using the adhesive backed grinding paper, which is much more cost effective than magnetic grinding paper. POLISHING: After your grinding procedure, we would recommend using our 12-inch ATLANTIS Polishing Pad with Magnetic Rubber (Part #: ATL-3012-MAG) along with 1 micron DIAMAT Polycrystalline High Viscosity Diamond Abrasive (Part #: PC-1001-500). The pads can go directly onto the magnetic base plates of the main unit. They are extremely easy to switch out and have a high life-span. NOTE: Should better polishing be required, we would suggest moving into the alumina diamond suspensions. Should need additional guidance, contact us today to learn more.

Question 28

What are the correct steps to calibrate the Ultrasonic Hardness Testing System?

Accepted Answer

Please refer to the below calibration steps for your Ultrasonic Hardness Testing System: Step 1: There are two HRC Blocks, one is 26.5, the other is 61.9. (Please check your block which may have a different value). Step 2: Measure the higher value hardness block first a few times. This will offer you a calculation of the average value. Note it down. Step 3: Press the &ldquo;Set&rdquo; button, the display shows &ldquo;E&rdquo;. That is the set state. In this case, if you press the SET button, there will be 4 group values. First: the high block value 61.9; second: the high profile value (which may be around 45 &ndash; this is set by factory to guarantee accuracy; third: the Low block value, 26.5; forth: is the low profile value, (which may be around 14 &ndash; this is also set by the factory to guarantee accuracy). When you calibrate the system, you need to only adjust the High profile value and the low profile value to correctly adjust the systems calibration. If on the first step when running your tests, you get a high average value of for example, 65; you need to adjust the high profile value to a higher value. It won&rsquo;t be (65-61.9=3.1), however, it may be 1,2,1.5,2.5. You will need to try it a few times to find the accurate value until you get your hardness block value of 61.9. When calibrating the low value, the same process applies. Adjust the profile value to a higher value, when the test value is lower than the block value.

Question 29

What makes an abrasive blade unique? What factors come into play when selecting a blade?

Accepted Answer

Abrasive blades are characterized by their abrasive type, bond type and hardness. The main factor when deciding which blade is right for you will be heavily dependant on your material hardness and whether it is a ferrous or a non ferrous metal.

Question 30

What are the two main types of abrasive sectioning blades?

Accepted Answer

Resin bonded blades and Resin-rubber bonded blades. Resin bonded have less smell, quicker wear, less sample burning and more versatile. Resin-rubber bonded blades certainly have a longer lifespan but will have a burnt rubber smell during the cutting process. They often burn a sample and are usually much more difficult in finding the best blade for the application.

Question 31

What blades can I use for my precision cutter?

Accepted Answer

Diamond wafering blades are the most common for precision sectioning, however, cubic boron nitride CBN blades are sometimes more efficient. Wafer cutting is often used for sectioning delicate samples or within a precise location.

Question 32

What are the main types of hot compression mounting resins? What colours are available and what are their uses?

Accepted Answer

Phenolic Resins (standard colors are black, red and green) &ndash; low cost and a variety of colours Acrylic Resins (clear) &ndash; excellent clarity Diallyl Phthalate Resins (blue and black) &ndash; provides a harder mounting support edge next to the specimen often used for coatings or heat treating sample analysis Epoxy Resins (glass-filled) &ndash; provides a harder mounting support edge next to the specimen often used for coatings or heat treating sample analysis Conductive Resins (phenolics with copper or graphite filler) &ndash; special resins can be made conductive for scanning electron microscopes SEM to prevent the specimen from building up a charge

Question 33

How do I determine which grits of metallographic abrasives and polishing pads/consumables to achieve the best finish for my specimen analysis?

Accepted Answer

The best way is to send NextGen your samples and have our metallographic experts work with your samples to working out the best consumables to achieve your desired finish. Contact a sales representative today to have your samples evaluated!

Question 34

What are the standard dimensions of your Rockwell Hardness Test Blocks?

Accepted Answer

The standard dimensions of the Rockwell C hardness test blocks are as follows: Square Rockwell Hardness Test Blocks Width: 50.90mm (~2&Prime;) Depth: 50.90mm (~2&Prime;) Thickness: 6.85mm (~0.25&Prime;) Request quote to get your consumables price catalogue.

Question 35

What are the standard dimensions of your Brinell Hardness Test Blocks?

Accepted Answer

The standard dimensions of the Brinell hardness test blocks are as follows: Square Brinell Hardness Test Blocks Length: 152.40mm (6&Prime;) Depth: 50.90mm (~2&Prime;) Thickness: 6.85mm (~0.25&Prime;) Request quote to get your consumables price catalogue.

Question 36

The etchants indicate an expiry date of roughly 3 months. What happens if these consumables are use past the expiry date?

Accepted Answer

After the 3 months expiry date, the etchants may still produce the expected results, with no apparent effect on quality. This is especially true if the etchants are stored in a cool, dark and dry environment. The issue is that not all of them will last longer than 3 months. Some of them will degrade to the point of being unusable around 90 days or so. Because of this, all etchants have a 3-month shelf life. Occasionally we advise customers to continue using their etchant until they no longer get the results they need. In other cases where safety is tightly regulated, they may not have this option. Learn more by contacting our Quality Consultants today.

Question 37

What is Diamond grinding paper and when is it used?

Accepted Answer

At 8000 HV, mohs 10, diamond is acknowledged as the hardest material around. Its structure is of cubic crystal. It is available either as an artificial or natural product. While diamond is perfect for coarse grinding, its cost renders it an ineffective grinding material for everything except hard ceramics. For metallographic purposes, specifically as a rough polishing abrasive, polycrystalline diamond is ideal.

Question 38

What is Zirconia grinding paper and when is it used?

Accepted Answer

Zirconium silicate or Zircon is a not-so-commonly used coarse grinding abrasive. Because of its extreme toughness, it lasts longer. But, it isn&rsquo;t, in general, as hard or sharp as the more popular abrasives. It thus needs a higher pressure to be effective. Usually, the 120 or 60 grit sizes are considered the most useful for metallographic grinding applications with Zircon. The particle size for metallographic abrasives is classified typically by their grit size or the average particle size measured in microns. Grit size refers to the particle size if sized or classified with mesh screens. Grit size, in general, represents the number of wire mesh or wires per given area. Larger grit numbers thus represent more or smaller mesh screen openings, and mean smaller particle sizes. For instance, a 120 grit particle is around 105 microns in size, while a 1200 grit particle is 2.5 microns in size. The variance between the P-grading system used in Europe and the more prevalent CAMI or ANSI standard is mainly due to the European number being based on how many openings there are if the wire mesh width is not considered in the calculation. For larger particles, therefore, Europe&rsquo;s P-grading is about the same as the CAMI or ANSI number. For example, 120 grit is equivalent to P120 grit. For finer particles, on the other hand, you will see a much bigger value such as P4000 grit compared to 12000 grit.

Question 39

What are the primary types of polishing pads?

Accepted Answer

CERMESH Metal Mesh Cloth &ndash; The wire mesh material is coarse as well as intermediate lapping/polishing. The wire&rsquo;s texture allows the abrasive be semi-fixed. It therefore offers the edge of minimizing damage while increasing stock removal. POLYPAD Polishing Pad &ndash; The synthetic polyester polishing pad works similar to a nylon pad, except that the Polypad is a lot more durable. It is ideal for use in intermediate polishing tasks. TEXPAN Polishing Pad &ndash; The pad is the most frequently used cloth for intermediate polishing jobs. The polishing pad is non-woven. CHEM 2 Polishing Pad (Black) &ndash; The porometric polymer pad has the same consistency of a rubber type of pad. The CHEM 2 Black pad possesses a low nap, but acts as a polishing pad for intermediate applications. Its performance is somewhere between that of a low nap pad and a high nap pad. DACRON II Polishing Cloth &ndash; The low nap type of polishing pad is primarily used for polishing with a 1 &ndash; 15 micron diamond abrasive. It is the most frequently used intermediate polishing pad for metals in Europe. It has a high nap that allows the pad to provide a very gentle and soft polishing action. GOLDPAD Polishing Pad &ndash; A low-napped pad for intermediate polishing applications, it is mainly used with a 1 &ndash; 9 micron diamond. ATLANTIS Polishing Pad &ndash; A low napped woven pad for final applications, it has a foam backing that allows for better matting to the sample. It is a superior polishing pad used with 1 &ndash; 6 micron diamonds. NYPAD Polishing Pad &ndash; The low napped polishing pad made from silk is ideal for intermediate polishing applications. It is used mainly with diamond intermediate abrasives. MICROPAD Polishing Cloth &ndash; The most prevalent high nap pad used for final polishing of most polymers and metals, the nap offers a very gentle and soft polishing action. TRICOTE Polishing Pad &ndash; The tight high napped pad is ideal for final polishing of most metal materials. It is equipped with a tighter nap compared to the MICROPAD Polishing Pad. MOLTEC 2 Polishing Pad &ndash; The wool polishing cloth is ideal for final polishing use, and comes with an extremely high nap. It is typically used for the final polishing of metals where edge retention is not a big factor. NAPPAD Polishing Pad &ndash; Another high napped variety for final polishing, the pad is mostly used form most polymers and metals. Compared to the MICROPAD, the NAPPAD has a higher nap that provides an extremely gentle polishing action. It is quite useful for polishing softer materials like aluminum, copper, and austentite steels. FELTPAD Polishing Pad &ndash; The thick felt pad is mainly used for the final polishing of glass and other area parts with large surfaces.

Question 40

What are the benefits of metallographic polycrystalline diamond polisher use in the polishing cycle?

Accepted Answer

Very uniform surface finish High cutting rates More uniform distribution of particle size The self-sharpening abrasives offer high removal rates Tougher/harder particles Blocky shape Hexagonal microcrystallites that are similarly hard in any direction Very rough surface because of more cutting points A surface area 300 times more than monocrystalline diamonds Absence of abrasion-resistant directionality as the abrasion is independent of the orientation of the particle

Question 41

What is the ideal use for polycrystalline diamonds in the polishing cycle?

Accepted Answer

Polycrystalline diamond is most efficient when used for the initial application of several diamond beads/extenders for pad wetting. Notice that the pad saturation is not necessary. Neither is it recommended. Additional dispensing is typically dripped on the surface at 1 to 2 drops per 10 to 15 seconds, depending on the speed of polishing and the sample?s surface area. For the preparation of mineral and ceramic specimens, the recommendation is the alternate dispensing of diamond and colloidal silica (or SIAMAT colloidal silica). This results to a chemo-mechanical polishing (or CMP) action that considerably improves removal rates, lowers subsurface damage, and makes the surface finish better. The technique is ideal for use with 6 micron diamonds and other smaller polycrystalline diamonds. For best results for the application, it is recommended to clean the samples and the cloth during the cycle?s final 15 seconds. Allow running water to flow on the surface of the polishing pad.

Question 42

What is the ideal application of Monocrystalline Diamonds in the polishing cycle?

Accepted Answer

The best use of monocrystalline diamond is during the initial application of several diamond beads/extenders for the initial pad wetting. Notice that the pad saturation is neither recommended nor necessary. Additional dispensing is typically dripped on the surface at 1 to 2 drops for every 10 to 15 seconds, depending on the sample?s surface area and polishing speed. For ceramic and mineral specimen preparation, it is best that colloidal silica and diamond be dispensed alternately. This results to a chemo-mechanical polishing action that considerably improves removal rates, lessens subsurface damage, and enhances surface finish. The technique is ideal for use with 6 micron diamonds and other smaller polycrystalline diamonds. For best results for the application, it is recommended to clean the samples and the cloth during the cycle?s final 15 seconds. Allow running water to flow on the surface of the polishing pad.

Question 43

What are the common abrasive sectioning blade types?

Accepted Answer

Resin bonded blades &ndash; more versatile, higher wear, less sample burning, and less smell Resin-rubber bonded blades &ndash; tends to burn the sample, burnt rubber smell, longer life, and harder to find the appropriate blade

Question 44

When should you use abrasive blades?

Accepted Answer

The selection of the right abrasive blade to use depends on the cut-off machine&rsquo;s design, and to a large degree, the preference of the user. In general, abrasive blades are characterized by the type of abrasive, hardness, and bond type. Determining the right blade depends on the material or hardness of the metal, and whether the metal is ferrous or non-ferrous. In common practice, it usually comes down to blade life and odor. Resin/rubber blades tend to smell more since the rubber will slightly burn during the cutting process. But, this type of blade wears more slowly, and thus lasts longer. Resin blades, on the other hand, don&rsquo;t produce the smell of burnt rubber and are more versatile. However, the break down more easily. Resin blades likewise offer a slightly better cut. This is because the abrasive is continuously renewed, producing a cleaner cut in the process. It is also worth noting that the traditional, old-fashioned technology used to produce abrasive blades resulted to highly specialized resin/rubber blades. Thus, finding the right resin/rubber hardness, blade thickness, and abrasive size that matches the properties of the sample as well as the cutting machine parameters required lots of experimentation and testing. In the past, the resin/rubber blade was more common in the US. However, with the improvement of resins in recent years, the trend has seen a gradual shift towards resin bonded types of abrasives. In contrast, resin bonded blades have been more popular in the Asian and European markets for many years now.

Question 45

What&rsquo;s precision cutting, and when is it used?

Accepted Answer

Precision wafer cut is most often applied with a diamond wafering blade. For some materials, however, cubic boron nitride (or CBN) is the more appropriate and efficient watering blade to use. Optimal wafer cutting is also done by optimizing the abrasive size and concentration, and choosing the most suitable cutting load and speed. Precision wafer cutting is applied to section extremely delicate samples and to section samples to a quite precise location. Typically, precision wafering saws are equipped with micrometers to accurately align and position the samples. They also have variable cutting land loading speed control. The typical precision wafering saw ranges in speed from 50 to 1500 rpm or 300 to 3000 rpm. Faster saws are needed to section extremely hard materials like treated steals, minerals, and ceramics.

Question 46

When is wafering sectioning used in lieu of an abrasive sectioning blade?

Accepted Answer

A diamond wafering blade is often used for sectioning delicate materials that require a precise cut. When sectioning with a wafering blade, it is important to consider the load, speed, and diamond size and concentration. The applied load and cutting speed are functions of the material to be cut. Commonly, diamond wafering is performed at a speed of anywhere between 50 and 5000 rpm with varying loads from 10 to 1000 grams. In general, a harder specimen is cut at a higher speed and load (for instance, minerals and ceramics) as well as more brittle samples are cut at lower speeds and loads (such as electronic silicon substrates). A number of factors must be considered when choosing the right watering blade, including the diamond concentration (high and low), diamond size (medium or fine), diamond bond (metal plate), blade thickness, and diameter. Diamond concentration is crucial since it affects the applied load directly during cutting. For instance, brittle materials like ceramics need a higher effective load to section, unlike ductile materials like metals that need more cutting points. Thus, low concentration blades are better when sectioning hard brittle materials like ceramics. On the other hand, high concentration blades are preferred for ductile materials that contain a large portion of plastic or metal. The diamond bonding material likewise considerably affects the cutting performance of the blade. A metal plated wafering blade requires periodic dressing to keep it in top performance. Contrary to what many people think, the cutting performance doesn&rsquo;t diminish when the diamond is taken out of the blade. The metal bond, in reality, mainly smears over the diamond, and blinds the diamond abrasive. The smeared material is taken away and the cutting rate is restored with periodic dressing.

Question 47

What are the main categories of compression mounting compounds?

Accepted Answer

The different types of compression mounting resins include: Acrylic Resins (clear) Phenolic Resins (available in standard colors of red, green, and black) Epoxy Resins (glass-filled) Diallyl Phthalate Resins (black and blue) Conductive Resins (phenolics w/ graphite or copper filler)

Question 48

Explain the main differences among different types of compression mounting compounds.

Accepted Answer

Phenolics &ndash; Generally, phenolics are utilized because of their comparatively low cost. Phenolics are likewise available in various colors. Acrylics &ndash; The primary use of compression mounting acrylics is due to its excellent clarity. It is particularly important in locating specific features in the specimen mount. Epoxies/Diallyl Phthalates &ndash; Glass-filled epoxy and diallyl phthalate are types of compression mounting resins utilized for providing a tougher mounting support edge around the specimen. The resins are typically used as support for the coatings&rsquo; edges, heat treated samples, as well as other specimens that require better flatness. There&rsquo;s no apparent gap between the mounting material and the specimen. The glass-filled epoxies offer excellent support to the edge of the specimen even in extremely hard samples. Specialized Compression Mounting Resins &ndash; The addition of fillers like copper or graphite enables the compression mounting compounds to be more conductive. A conductive mount is used for scanning electron microscopes (SEM) to keep the specimen from accumulating a charge. A conductive mount is also used for samples that require electrolytic etching or polishing.

Question 49

What is a Silicone Carbide Grinding paper and when is it used?

Accepted Answer

SIC abrasive is manufactured using the high temperature produced in the reaction between carbon and silica. Its structure has a hexagonal-rhombohedral crystal shape. Its hardness is around 2500 HV. The abrasive is ideal for grinding and cutting because of its sharp edges and hardness. It likewise has enough brittleness. It easily cleaves to create new sharp edges (self-sharpens). SIC is superior in maximizing the cutting rates, while helping minimize subsurface and surface damage. In metallographic applications, it is used in abrasive blades as well as for coated abrasive grinding paper that range from the extremely coarse 60 grit to the extremely fine 1200 grit size. Coated or bonded SIC abrasive papers are specifically designed to give the abrasive a big number of cutting points. This is possible by proper alignment of the abrasive particles that are about normal to the backing. It must be noted that coated abrasives aren?t quite coplanar. SIC papers thus produce maximum efficiency (stock removal, cut rate, and minimal damage) since new abrasive gets exposed and the old abrasive is broken down.

Question 50

What is Alumina grinding paper and when is it used?

Accepted Answer

A naturally occurring material, Alumina comes in either the alpha (hard at 2000 HV, mohs 9) or the gamma (soft at mohs 9) phase. The Alumna abrasive is mainly used for final polishing due to its durability and hardness. Unlike SIC abrasive, alumna is easier to break down into colloidal or submicron particles. It is worth noting that bigger coated or bonded grit alumina sizes are available commercially. But, they are not recommended for metallurgic uses because they turn dull. This results to a lower cut rate and a higher subsurface and surface damage.

Question 51

What is the expected useful life of hardness blocks?

Accepted Answer

While some blocks sometimes self-destruct within a short period due to heavy use, some can last for several years. In general, high force testing can destroy soft blocks in about a month, particularly when it requires daily verification. Changes in ISO and ASTM requirements can render a block useless. This is what happened to pre-NIST traceable HRC back in 2000, as well as blocks calibrated in the absence of verified indenters pre-E180-07.

Question 52

I ordered a 300 HV 0.5 microindentation test block, but got a 370 HV 0.5 instead. I intend to use it for checking a special part I&rsquo;m fabricating. Wouldn&rsquo;t it be possible for me to get exactly the value I need?

Accepted Answer

You use test blocks to verify the calibration of the tester, and not your part. Although it is ideal to use a block that&rsquo;s as close as possible to your part&rsquo;s hardness, it isn&rsquo;t that critical. That being said, blocks are selected from different heat treat lots to get the best possible match. Different indenter and force combinations can likewise affect the result of your received block value. It is recommended that you consider the suggested hardness levels listed in ISO and ASTM documents.

Question 53

How can if determine the proper hardness scale to use?

Accepted Answer

You can start with the part specifications with your customer or within your organization. Part specifications are sometimes listed with common scales like HRC, although you can&rsquo;t do the scale on your part &ndash; the reason being the part may be too thin or possesses a case hardness. ISO and ASTM charts provide guidance on the minimum thickness. Take care when using testers by conversion or those that convert hardness scales electronically. Conversions cannot be accredited.

Question 54

What does a master calibration kit include?

Accepted Answer

The Master Calibration Kits we produce give customers the ultimate Quality Control tool. Every kit contains test blocks or a single block, as well as the penetrator unit used for calibrating them. Matching the blocks to a particular penetrator establishes a set relationships, which can then be disregarded as probable variables in hardness test systems. If a problem crops up, an available master kit lets you accurately and promptly determine if the source is your hardness tester. All the blocks that come with our kits have been calibrated using a tester, the accuracy of which has been verified with NIST traceable depth and load measuring devices. The kits come with a polished wood case, as well as certificates that cover all applicable standards.

Question 55

Do Brinell test blocks have circles and grids?

Accepted Answer

Circle and gridded blocks are sold separately. The most common block dimensions are 6 x 2 x &frac34;&rdquo;. Other available dimensions 2 x 2&Prime; and 6 x 4 1/2 x &frac34;&rdquo;, depending on ASTM E10-17 dimension rules. Call to check for availability and prices. Materials used are brass, aluminum, or steel, depending on the hardness required.

Question 56

WHAT ARE THE STANDARD DIMENSIONS OF YOUR VICKERS HARDNESS TEST BLOCKS?

Accepted Answer

Vickers Hardness Test is a flexible hardness test technique that is used to measure both macro and microhardness. It is appropriate for a variety of applications and materials and has a wide load range. A lot of people believe that the Vickers hardness test is simpler to use than other hardness tests for the following reasons: The procedure can be carried out using a universal or micro hardness tester; The calculations necessary are independent of the indenter size; The same indenter (a pyramidal diamond) can be used for all materials, regardless of hardness. Your indentation will deform the surrounding material and change its properties when you do a Vickers hardness test, regardless of the microhardness tester you employ. The Vickers hardness testing standards specify a specific distance between multiple indentations in order to prevent errors in interpreting perceived hardness. These are the standard dimensions of NextGen&rsquo;s Vickers Hardness Test Blocks: Micro Vickers &ndash; 1kg. or under Range: from 80 UVN &ndash; 2200 UHN Diameter: 1.25&Prime; Heavy Load Vickers &ndash; from 1kg. &ndash; 50kg. 2.0&Prime; Square &ndash; 50 x 50mm 1/4&rdquo; Thickness &ndash; 6.35 mm Range: 80 UHN &ndash; 800 For 800 & up 1.25&Prime; diameter (32mm) Looking for a quote? Click here to obtain a personalized quote!

Question 57

WHAT ARE THE STANDARD DIMENSIONS OF YOUR KNOOP HARDNESS TEST BLOCKS?

Accepted Answer

The Knoop hardness test is used for microhardness testing (loads less than or equal to 1 kgf). Hence before putting the sample material into the microhardness tester, its surface should be highly polished or electropolished. In the microhardness testing range, the Knoop hardness test is an alternative to the Vickers hardness test and can be carried out on the same universal or micro hardness testing apparatus. It is primarily employed to prevent breaking in brittle materials and to make it easier to measure the hardness of thin layers. The indenter used in the Knoop hardness test is a pyramidal diamond, just like in the Vickers hardness test. However, the pyramid is extended rather than symmetrical. The length diagonal of the indent is measured optically to determine the Knoop Hardness (HK). These are the standard dimensions of NextGen&rsquo;s Knoop Hardness Test Blocks: Micro Knoop &ndash; 1kg. or under Range: from 80 KHN 700 Diameter: 1.25&Prime; Heavy Load Knoop &ndash; from 1kg. &ndash; 50kg. Range: from 80 KHN &ndash; 700 1.25&Prime; Square Looking for a quote? Click here to obtain a personalized quote!

Question 58

What&rsquo;s the benefit of the grid over circle spacing for Rockwell test block testing?

Accepted Answer

Square Pattern &ndash; The entire block is grid patterned. The problem with this design is that soft blocks create bigger indents, and don&rsquo;t always satisfy ASTM E18-17e1 for the distance between the edge and another indent. You can use any other square to solve the issue. Circle Pattern &ndash; The design solves the distance problem between indents, thereby meeting the standard. There are complaints of excessive space wastage. This, however, is the ASTM E18-17e1 rule.

Question 59

When fabricating test blocks, how do you guarantee compliance with set industry standards?

Accepted Answer

We directly work with brass and steel mills for the specific chemical composition. We perform all machining processes in-house, at the calibration site. These include grinding, lapping, and polishing. We perform 100% inspections to make sure each single test block meets ASTM physical requirements in terms of flatness, thickness, parallelism, and surface roughness. Each Rockwell test block supports compliance to NADCAP.

Question 60

Which certifications are your test blocks compliant with?

Accepted Answer

The test blocks are manufactured in an ISO/IEC 17025 accredited lab by the American Assoc. for Lab. Accreditation (A2LA).

Question 61

At what scales do you produce test blocks?

Accepted Answer

Rockwell Regular & Superficial scales Vickers Micro-indentation &ndash; for loads starting from 10gf up to 1kgf Vickers Micro-indentation &ndash; for loads starting from 1kgf up to 120kgf Knoop Micro-indentation &ndash; for loads from 10gf up to 1kgf Brinell: HBW5/250, HBW10/1000, HBW5/750, HBW2.5/62.5, HBW2.5/187.5, and HGW10/3000.

Question 62

What do you recommend for verification testing in-house?

Accepted Answer

Ensuring compliance to ISO, ASTM, and JIS standards is crucial in user-performed hardness testing. The standard under which the lab operates determines the frequency. Common reasons for performing verification tests include: Start of production for the day Changing test force Changing indenters

Question 63

What&rsquo;s the proper indentation spacing on Rockwell and Brinell test blocks?

Accepted Answer

Based on JIS, ASTM, and ISO standards, the proper distance between 2 adjacent indentations&rsquo; centers is a minimum of 3 times the indentation&rsquo;s diameter. The distance any indentation&rsquo;s center to a test piece edge must be a minimum of 2 &frac12; times the indentation&rsquo;s diameter.

Question 64

What&rsquo;s the proper spacing for Vickers test block indentations?

Accepted Answer

Based on ASTM Standards, measuring the distance between 2 indents or the edge of a test piece and an indent involves at least 2 &frac12; times the indentation&rsquo;s diagonal (dV). Based on JIS and ISO standards, the distance between 2 indent centers is a minimum of 3x the indent&rsquo;s diagonal for copper, copper alloys, and steel, and a minimum of 6 times for lighter metals, tin, lead, as well as their alloys. The distance from an indent&rsquo;s center and the test piece edge must be a minimum of 2 &frac12; times the dV for copper, steel, and copper allows, and a minimum of 3x for light metals, tin, lead, as well as their alloys.

Metal Testing Equipment

Categories

Products

Products

NG - LeebGen 3000 - Leeb Rebound Portable Hardness Tester

Ultrasonic Contact Impedance Hardness Tester - UH200

NextGen Telebrineller Brinell Hardness Testing System

Surface Roughness Testers

Hardness Test Blocks, Indenters and Hardness Testing Accessories

Metallography Consumables

Portable Hardness Testers

Metal Testing Equipment

Categories

Products

Products

NG - LeebGen 3000 - Leeb Rebound Portable Hardness Tester

Ultrasonic Contact Impedance Hardness Tester - UH200

NextGen Telebrineller Brinell Hardness Testing System

Surface Roughness Testers

Hardness Test Blocks, Indenters and Hardness Testing Accessories

Metallography Consumables