Method for testing performances of all components in heterogeneous material based on nano-scratch technology

Abstract

The invention discloses a method for testing the performances of all components in a heterogeneous material based on a nano-scratch technology, and belongs to a method for testing the performance of micro-nano scale materials. The method comprises the following steps: inlaying, grinding and polishing the measured heterogeneous material to produce a sample for nano-indentation and nano-scratch; keeping a pressure head at a constant scratching depth through a feedback adjustment technology, and carrying out scratch operation in a parallel manner, an equal interval manner and an equal depth manner to make the pressure head sequentially scratch into a left phase, a boundary phase and a right phase; obtaining the starting point position and the end point position of every scratch transition area according to a contact mechanics judgment criterion; and adopting the reciprocal of the measured contact stiffness as the ordinate, drawing all points through origin, linearly fitting all the points, and calculating the reciprocal of the obtained straight slope to obtain the elastic modulus of the right phase. The method has the advantages of effectiveness in judgment of the width of the boundary phase at a certain depth in a typical area, avoiding of the influences of the boundary phase, improvement of the experiment precision, and obtaining of the performances of all the components in theheterogeneous material, not affected by the circumference effects.

Description

technical field [0001] The performance testing technology of various components of heterogeneous materials based on the nano-scratch method belongs to the performance testing method of micro-nano scale materials. Background technique [0002] Micro-nano-scale heterogeneous materials include not only the pure phase formed by each component, but also the non-uniform boundary riveted together, and the interfacial phase is often defined as the riveted region. The results measured by nanoindentation experiments on heterogeneous materials not only include the mechanical properties of the pure phase of heterogeneous materials, but are also affected by the interface phase. This is because the observation means of the nanoindentation instrument is an optical microscope, which cannot clearly judge the width of the interface phase. At this time, the nanoindentation mechanical property test of the pure phase is often blind. [0003] Conventionally, the interface contour can be collecte...

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Problems solved by technology

[0008] First, the conventional contact scanning method (atomic force microscope or nanoindentation instrument) can obtain the contact stiffness or contact force according to the scanning, and then calculate the elastic modulus of the left and right phases, but the measured results will be affected by the surface properties. Influence, and it is impossible to accurately distinguish the test results of the phases of non-uniform materials in a certain area

[0009] Second, the conventional method to obtain the mechanical properties of each phase of a heterogeneous material is to observe the interface between the left phase and the right phase through an optical microscope, and then perform positioning indentation. This method cannot determine whether it is the left phase or the right phase at a certain depth. , the measured results are affected by the uncertain base effect

When observing, the indentation is often inaccurate, and one indentation needs to compare images repeatedly, which is difficult to analyze and the test efficiency is very low

[0011] Fourth, the conventional scratching method using a nanoindenter controls the scratching process through the change of the normal phase force, which makes the scratching depths different on different phases of heterogeneous materials, that is, when scratching on different phases, the indenter and the test The relative positions of the phases are different, which makes it impossible to obtain the width of the interface phase by the criterion of contact mechanics

[0012] Fifth, in the conventional method of scratching non-uniform materials by nano-indentation instrument, the effects of base effect and peripheral effect, sample roughness, sub-surface damage caused by grinding and polishing, surface viscosity, protrusion or depression are not constant, The interfacial phase width measured by non-constant depth scratches is difficult to analyze, and quantitative conclusions cannot be obtained

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