Micro-nano indentation experiment method for fiber-reinforced composite

Abstract

The invention discloses a micro-nano indentation experiment method for a fiber-reinforced composite and belongs to the technical field of micro-nano mechanical testing. A fiber-reinforced composite under test is subjected to embedding prior to grinding and polishing so as to obtain a test sample of nano indentation and nano scratch; a start of scratch is a center point of a circular area; a constant scratch depth is kept for a presser by means of feedback adjustment; a series of equal depth scratches are made from the center point of the circular area sequentially through fiber, an interfacialphase and a base. Start and end point positions of the interfacial phase of each scratch are acquired through contact mechanics judging rules; the start and end points of the interfacial phase are sequentially connected by lines, and accordingly morphology of the interfacial phases is acquired. The method of the invention has the advantages that interfacial phase width of a typical area under certain depth can be effectively judged; when the indentation depth is less than the scratch depth, entry of the indentation in the interfacial phase is avoided, experiment precision is improved, and micro-nano indentation properties of the fiber-reinforced composite with no influence of peripheral effect are acquired.

Description

technical field [0001] The invention relates to a micro-nano-scale indentation experimental method for fiber-reinforced composite materials, which belongs to the technical field of micro-nano mechanical testing, in particular to a method for conducting experiments with a nano-indentation instrument. Background technique [0002] The interface between fiber and matrix in fiber-reinforced composites is a riveted and irregular boundary, and the interfacial phase is often defined as this riveted area. The nanoindentation experiment in this area obtains the mechanical properties under the interaction between the fiber and the matrix, and the experiment usually needs to obtain the properties of one of the phases in the composite material. Since the observation means of the nanoindentation instrument is an optical microscope, when the width of the interface phase cannot be judged, the nanoindentation mechanical property test of the pure phase is often blind. [0003] Conventionall...

AI Technical Summary

Problems solved by technology

This method is inaccurate in judging the position of the indenter, and needs to compare images repeatedly for an indentation, making analysis difficult and testing efficiency very low

[0009] Fourth, the conventional scratching method using a nanoindenter is to control the scratching process through the change of the normal phase force, which makes the depth of the scratches on different phases of fiber reinforced composites different, that is, when scratching on different phases, the indenter The position relative to the sample is different, which makes it impossible to obtain the width of the interfacial phase by the criterion of contact mechanics

[0010] Fifth, in the conventional method of scratching fiber reinforced composite materials by nanoindentation instrument, the effects of base effect and peripheral effect, sample roughness, subsurface damage caused by grinding and polishing, surface viscosity, protrusion or depression are not constant , the transition zone measured by non-constant depth scratches is difficult to analyze, and quantitative conclusions cannot be drawn

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