Tag: ASTM E384

ASTM E384 2016 Edition Released

ASTM E384, “Standard Test Method for Microindentation Hardness of Materials,” has just been revised.  The new 2016 Edition is available in a variety of formats from Document Center Inc., an authorized distributor of the ASTM standards.  The new Edition replaces the 2011 Edition (with an editorial change from 2012), which is now obsolete.  This is a major revision and should be purchased by all users of this publication.

The ASTM E384 provides you with the details of performing both the Knoop and Vickers microindentation tests.  However, you will notice that the title has changed from the previous edition to focus back on the microindentation test itself, rather than to limit it to just Knoop and Vickers.  This is a test that involves the use of a diamond indenter and a calibrated machine that applies force to the  material in question using this indenter.  A hardness number is then determined using calculations provided in this document.

If you’re using the ASTM E384, you’re wondering what has changed in this new revision.  Let’s put it this way, what hasn’t changed?  There’s not 1 page of technical material that has not been revised.  In fact much of the technical information has been completely rewritten.  For this reason, you may want to purchase the redline edition of the document.  This will provide you with a clean copy of the 2016 Edition along with a “marked-up” copy of the previous 2011e1 Edition.

Now the next question is where to purchase your copy.  Use Document Center’s webstore at www.document-center.com to search for and order any ASTM standard.  Here’s a direct link to the order page for ASTM E384.  You’ll see that you can order both the paper format and a pdf download online.  If you’d like enterprise-wide access to any ASTM standard, check in with our staff for information on setting up a Standards Online service.  This allows you to access the standards you need on our cloud-based platform.  You can reach us by phone at 650-591-7600 or by email at info@document-center.com.

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New ASTM E384 2011 Edition released on Standard Test Method for Knoop and Vickers Hardness of Materials

ASTM E384 2011 Edition, titled “Standard Test Method for Knoop and Vickers Hardness of Materials,” has been released.   This 43-page test method covers determination of the Knoop and Vickers hardness of materials, the verification of Knoop and Vickers hardness testing machines, and the calibration of standardized Knoop and Vickers test blocks.

Hardness tests have been found to be very useful for materials evaluation, quality control of manufacturing processes and research and development efforts.  Hardness, although empirical in nature, can be correlated to tensile strength for many metals, and is an indicator of wear resistance and ductility.

Because the Knoop and Vickers hardness will reveal hardness variations that may exist within a material, a single test value may not be representative of the bulk hardness.

The Vickers indenter usually produces a geometrically similar indentation at all test forces.  Except for tests at very low forces that produce indentations with diagonals smaller than about 25 μm, the hardness number will be essentially the same as produced by Vickers machines with test forces greater than 1 kgf, as long as the material being tested is reasonably homogeneous.  For isotropic materials, the two diagonals of a Vickers indentation are equal in size.  Recommendations for low force microindentation testing are also included in Appendix X5.

The Knoop indenter does not produce a geometrically similar indentation as a function of test force.  Consequently, the Knoop hardness will vary with test force.  Due to its rhombic shape, the indentation depth is shallower for a Knoop indentation compared to a Vickers indentation under identical test conditions.  The two diagonals of a Knoop indentation are markedly different.  Ideally, the long diagonal is 7.114 times longer than the short diagonal, but this ratio is influenced by elastic recovery.  Thus, the Knoop indenter is very useful for evaluating hardness gradients or thin coatings of sectioned samples.

The ASTM E384 and all ASTM test methods are available on Document Center’s website, www.document-center.com.  Additionally we have many obsolete revisions of the ASTM standards available.  You may prefer to contact us by phone (650-591-7600), fax (650-591-7617) or email (info@document-center.com) if you have any additional questions.