OUR LABORATORY IS EQUIPPED WITH VARIOUS EQUIPMENT AND CAN MEET VARIOUS REQUIREMENTS OF CHEMICAL ANALYSIS AND METALLOGRAPHIC ANALYSIS.
FOR THE SELECTED INSTRUMENT, WE ILLUSTRATE THE FEATURES IN DETAIL, THE OPERABLE FUNCTIONALITY AND ANALYSIS, IN COLLABORATION WITH Tecnologie Superficiali Srl.
VICKERS MICRODUROMETER
What is an Microdurometer and what is it used for?
The microdurometer is a laboratory instrument capable of measuring the hardness of almost all types of metallic materials starting from the most tender or of low thickness to the hardest, obviously including those subjected to surface treatment. Our tool provides the hardness reading expressed on the Vickers scale (HV) which is designed to test all types of metals from very soft to very hard.
Among the most common methods of measuring the hardness, the Vickers hardness test is the most accurate in terms of accuracy and repeatability.
The technology complies with ISO 6507-1 measurement methods.
Our laboratory is equipped with a Future Tech FM-700 microdurometer.
What can we analyse at Metalcoating?
All types of metallic materials starting from the most tender or of low thickness to the hardest, obviously including those subjected to surface treatment.
We have a microdurometer, or micro-Vickers hardness tester, at low load for universal use which allows us to carry out analysis for:
- Calculation of the surface hardness of the entire sample or parts thereof
- Calculation of micro hardness on samples or parts thereof, embedded in resin or similar
What are the characteristics that an analysis sample should have?
Sample preparation is the procedure that allows for its further analysis.
This procedure consists firstly in sectioning the sample, possibly reducing it in size, (the maximum sample size is 50 x 70 x 100 mm) in such a way that it can be inserted in the grip of the microdurometer, or incorporate them in the phenolic resin, or, to be able to display the hardening profile.
For the reduction of the size of the test sample a cutting metallographic is used, using a different wheel according to the following characteristics:
– Hardness,
– The material dimension
– Precision cutting
What is the surface hardness?
The hardness H (hardness) is the resistance that the surface of a material opposes to its penetration. The hardness influences the resistance to scratching, to wear, to cutting and sometimes also to corrosion, and varies both by type of material, and by type of heat treatment undertaken (and therefore for the type of microstructure).
Usually the first analysis that tends to be carried out on a material is the surface hardness test: in fact, in addition to being the simplest and fastest, it is also the least destructive. In fact it is rarely necessary to treat the sample in a particular way before subjecting it to testing. This test is based on the footprint size on the surface of a sample left by a correctly loaded indenter.
What is micro-hardness
With microdurometer the test is performed by applying low load on a pyramid-shaped Vickers indenter (from 10 to 1000 g). You can measure the footprint size either by means of the same instrument equipped with a built-in automatic analyser, or through the use of the optical microscope fitted with a camera. In the second procedure, we use advanced software for image analysis (NIS Elements BR) that allows us to make accurate measurements and obtain high-resolution images that can be stored and compared over time.
The calculation of the micro hardness is used primarily to obtain a higher accuracy (compared to the measurement of the surface hardness); it also allows you to accurately detect the profile thickness of the effective hardening and measure the hardness in areas, micro-structurally if they seem abnormal.
Principle of operation
The microdurometer is a laboratory instrument capable of measuring the hardness of almost all types of metallic materials starting from the most tender or of low thickness to the hardest, obviously including those subjected to surface treatment. Our tool provides the hardness reading expressed on the Vickers scale (HV) which is designed to test all types of metals from very soft to very hard. The indenter is made from a diamond cut in a square pyramid with an opening of 136°. As for the Brinell scale, the hardness value is obtained as the ratio between the force exerted and the tread surface of the penetrator.
This tool is used mainly for testing the hardness on small pieces and high precision, hardened surface layers and surface coatings.
The reading and measurement (under a microscope or automated in the same instrument) of the diagonals of the rhombus resulting from the impression left by the penetrator is used to define, according to specific simple calculations, as a function of the applied load, the hardness value HV. The proper preparation of the specimen is an essential element to make a correct measurement.