Views:316 Author:Site Editor Publish Time: 2021-11-16 Origin:Site
Micro hardness tester is often used to measure the hardness of individual phases in a material or very thin layers on a metal surface (e.g. plating, nitride layer). Its value can be expressed as Mohs hardness HM, Vickers hardness HV or Nuptial hardness HK. The specimen must be ground and polished to a bright flat surface, eroded to expose the microstructure, and then tested and observed under the micro hardness tester.
Here is the content list:
1.What are the operating conditions of the micro hardness tester?
2.What are the components of the micro hardness tester?
3.What is the working principle of micro hardness tester?
Micro hardness tester should work in the temperature range of 20℃±8℃, humidity should be kept within the range of ≤70%, it is strictly forbidden to use in the environment of dripping water or dust, moreover, it should not be used in the environment of corrosive gas and radiation. Micro hardness tester should be fixed in a fixed position, not suitable for frequent handling or carrying use.
The micro hardness tester is composed of main unit, microscopic eyepiece, various test benches, standard hardness block, various indenters, objective lens, leveling angle, etc.
The microscopic eyepiece is used to observe metallographic or microstructure, determine the test site, measure the diagonal length, data acquisition, etc.; the main body of the micro hardness tester is to complete the switching of the eyepiece and indenter, apply the load at the determined test site, complete the movement of the platform to find the image point, etc.; the related accessories are mainly for the clamping stability of the test piece, etc.
The micro hardness tester is to press the diamond quadrilateral cone indenter with the angle of 136° on the two opposite sides into the surface of the specimen under the action of certain test force, keep a certain time, remove the test force, measure the diagonal length of the indentation, and then check the diagonal length and micro hardness value correspondence table to get the micro hardness test value.
This test principle is a simplified test operation process. The true micro hardness is the quotient obtained by dividing the test force by the conical surface area of the indentation, which can be calculated from the indenter cone angle and the indentation diameter, and finally the micro hardness formula is obtained, where HV refers to the micro hardness value, F refers to the test force, and d refers to the indentation diameter. The diagonal length of the indentation and the corresponding table of micro hardness tester values are calculated from the formula.
The loads used for micro hardness tester and Vickers hardness tester are 1kg, 2kg, 3kg, 5kg, 10kg, 20kg, 30kg, 50kg, 100kg, 120kg, etc. The commonly used ones are 1kg, 2kg, 5kg, 10kg, 30kg, 50kg. The size of the load depends mainly on the thickness of the test piece.
The final hardness of the test is expressed by the load that can be applied to the indentation unit area. The selected fixed experimental force (load) is pressed into the surface of the specimen, and after a specified holding time (load retention), and then after removal of the experimental force (unloading), a square quadrilateral or Knupp indentation with a square base remains on the surface of the specimen, and the length of its diagonal is measured through a micrometer eyepiece to obtain the area of the indentation, and the micro hardness value is the ratio of the experimental force to the surface area of the indentation.
A micro hardness tester is a precision instrument for metal material property inspection in machinery, metallurgy, and other industries, and its working principle is relatively easy to understand. EBPu Electromechanical Equipment (Zhejiang) Co., Ltd. is a key private enterprise in Wenling's high technology industries. They are committed to becoming the most satisfied supplier to our partners & clients. So if you want to buy micro hardness tester, I think you can find the product that satisfies you in this company.