Microhardness Testing (Vickers & Knoop)

CAMS
Computer Upgrade for Micro Testers

HMV-2
Advanced Micro

HMV-M
Basic Micro

MT-90
High-Speed Case Depth System

HSV
Macro Vickers

Download complete product literature for these testers: Select the link, then "Download Literature".

Also see links for DataView, Test Blocks, and Rockwell Accessories. (Accessories are listed under each product.)
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The Fundamentals of Microhardness Scale Testing

The Microhardness test procedure ASTM E-384 specifies a range of light loads using a diamond indenter to make an indentation which is measured and converted to a hardness value. It is very useful for testing on a wide type of materials as long as test samples are carefully prepared. There are two types of indenters, a square base pyramid shaped diamond for testing in the Vickers scale and a narrow rhombus shaped indenter for the Knoop scale. Typically loads are very light, ranging from a few grams to one or several kilograms, although "Macro" Vickers loads can range up to 30 kg or more. The Microhardness methods are used to test on metals, ceramics, composites - almost any type of material.

Since the test indentation is very small, the Microhardness testing is useful for a variety of applications: testing very thin materials like foils or measuring the surface of a part, small parts or small areas, measuring individual microstructures, or measuring the depth of case hardening by sectioning a part and making a series of indentations to describe a profile of the change in hardness. The Vickers method is more commonly used. The Knoop method is commonly used when indentations are closely spaced or testing is close to the edge of a specimen due to the narrow shape of the indentation. The width of the Knoop indentation can provide more resolution for measurement and the indentation is also less deep so it is useful for thinner materials.

There are a number of considerations in Microhardness testing. Sample preparation is usually necessary in order to provide a specimen that can fit into the tester, make a sufficiently smooth surface to permit a regular indentation shape and good measurement, and be held perpendicular to the indenter. Usually the prepared samples are mounted in a plastic medium to facilitate the preparation and testing. The indentations should be as large as possible to maximize the measurement resolution. (Error is magnified as indentation sizes decrease) The test procedure is subject to problems of operator influence on the test results.

Also see the General Hardness Training Guide: Part 1 Part 2 Part 3

For a complete knowledge of the Microhardness testing users should obtain the ASTM standard E-384 which describes both Vickers and Knoop testing.

How Newage Testers Can Improve Your Microhardness Testing

Microhardness testing often presents challenges for users. The test procedure is lengthy and requires skilled personnel so it is expensive to perform. The test result is subject to operator influence. Newage testers can provide answers to these and other challenges in micro testing.

TEST ACCURACY		CAMS		An automatic measurement of the indentations removes operator influence. When measuring manually on-screen resolution provides a larger image for more accurate measurement.
		MT-90		The MT90 removes the operator from the measurement process using a Rockwell-like depth of indentation measurement.

TEST SPEED		HMV-2		The HMV-2 provides automatic turret and other options to reduce operator's workload
						MT90	The MT90 can perform an entire case depth analysis in a few minutes with a test cycle of six or seven seconds.
		CAMS		Automatic measurements and automatic documentation can speed up testing. Using CAMS with the motorized tables enables traverses

	DOCUMENTATION		MT90		MT90 stores predefined test sequences and can store and chart data from a near infinite number of tests or traverse sequences.
		CAMS		MT90 stores predefined test sequences and can store and chart data from a near infinite number of tests or traverse sequences.
		HMV-2		The HMV-2 can store test results in multiple files and do statistical analysis for data in each file.

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To purchase a copy of the complete Microhardness test method standard, designated E384, contact ASTM
Books describing hardness testing are available from a number of organization such as ASM International