Hardness testing method and usage thereof

Abstract

A hardness testing method is characterized in that during hardness testing, a special testing pressure head with a plane end is used for applying load to an object to be tested, corresponding indentation is formed on the testing surface of the object to be tested, and the indentation and the added load are used as basis for hardness testing. The technical problem of hardness testing for representative multiple composites is solved creatively, and accordingly, different indentation area calculation modes and methods are developed by using a hardness testing system. The testing method is compatible and complementary with a traditional hardness testing method, so that testing (hardness) values obtained by using the methods can be compared, and a testing reference system is provided for hardness ratio of the composites to homogenous materials.

Description

technical field [0001] The invention relates to the technical field of hardness testing methods and design of hardness testing devices, and in particular provides a hardness testing method, which is especially suitable for hardness testing of multi-component composite materials. [0002] Background technique [0003] Composite materials are different from homogeneous materials, and the detection of mechanical properties has its particularity. For composite materials with different reinforcement (strength, toughness) phases, the mechanical performance detection is also different. Reinforcement phase composite materials are generally tested for compression or bending resistance. Ductile phase composite materials can generally only be tested for tensile strength, and hardness testing has always been difficult for most composite materials, especially the hardness testing of metal matrix composites with double continuous reinforcement (three-dimensional overall foam ceramic skel...

AI Technical Summary

Problems solved by technology

[0004] Hardness testing is basically non-destructive testing. After testing, it generally does not affect the performance and use of the inspected piece. Generally, it can perform 100% testing on workpieces or materials. It is convenient, simple, and fast to operate. It is the most basic and efficient engineering material (workpiece). One of the most commonly used and common mechanical performance testing indicators, especially in the matching selection of friction pairs and material selection under wear conditions, the hardness testing index is one of the most important and necessary testing items, but due to the combination Due to the heterogeneity of materials, the currently widely used hardness measurement methods (cloth, Rockwell, Vickers, Shaw, Richter, etc.) and equipment are not suitable for the following reasons:

[0005] 1. The composite material is discontinuous and homogeneous, and the indentation area produced by the indenter of the hardness tester currently used cannot cover the reinforcement, tough phase and matrix (such as the indentation of Low, Wei, Xiao, Li and microhardness), and the obtained hardness The value may be the hardness value of the matrix or reinforcement, ductile phase individual, not the overall (macroscopic) hardness of the composite material

[0006] 2. Composite materials are generally a combination of two materials with large performance differences. There is a large difference in strength and toughness. The indentation depth produced by the indenter of the hardness tester currently used is uneven, and there is a certain amount of plastic deformation. The indentation area produced by the gauge indenter may cover the reinforcement, tough phase and matrix, and the indentation deformation with a large uneven depth may cause a group of components with higher hardness and poor plasticity to be crushed in the composite material, resulting in The obtained hardness value is contrary to the basic concept of hardness testing, resulting in distortion of test data and test failure

[0007] In summary, so far there is no feasible, effective, applicable and correct hardness testing method for the above materials

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