ASTM E384

Knoop Micro-Hardness Testing Services

Purpose: Measure the micro-hardness of a metal sample per ASTM E384.

Sample: One sample 0.010 inches (0.25 mm) square or larger.

Price & Delivery: Contact us for a quote.

Basic Description: ASTM E384 is a method of measuring micro-hardness by pushing a pyramid shaped diamond indenter into a metal and then measuring the size of the indent using a microscope. Usually the sample is cross sectioned, mounted (ASTM E3) in epoxy, and polished to a mirror finish before testing. This method covers Knoop micro-hardness using an elongated pyramid indenter and Vickers micro-hardness using a square (equilateral) pyramid indenter. The indenter is pushed into the sample using a fixed load which is usually 500 grams but loads ranging from 10 to 1000 grams may be used. Large and non-uniform samples can be better measured using ASTM E18 Rockwell Hardness or ASTM E10 Brinell Hardness. Knoop micro-hardness is used to measure the hardness of areas as small as 0.0015 inches in size (0.05 mm). Hardness profiles from the surface to the core of a sample allow measurement of effective case depth or depth of decarburization. High surface hardness will give good wear resistance but a softer core is normally required to preserve ductility (impact strength). Results are reported in a table with up to ten indents per sample.

Limitations: The sample must be polished to a mirror finish and is usually cross sectioned and mounted (ASTM E3) in epoxy prior to testing. Non-uniform materials often give inconsistent results. Samples less than 0.0015 inches (0.05 mm) thick are usually too thin for accurate measurements.

Equipment: Mitutoyo MVK-H1 Microhardness Tester

Method Publisher: https://www.astm.org/e0384-17.html

Keywords:

• Knoop Micro-Hardness
• Knoop Hardness
• Vickers Micro-Hardness
• Vickers Hardness
• Case Depth
• Micro-Indentation Testing
• Hardness Testing