Method for correcting mechanical parameters of perpendicularity of flat pressing head to indentation test material

Abstract

The invention relates to a method for correcting the mechanical parameters of the perpendicularity of a flat pressing head to an indentation test material, which belongs to the field of material mechanical property testing. The perpendicularity of the flat pressing head relative to the surface of a test piece in an indentation test is measured by an ultra-precision perpendicularity measuring instrument. The flat pressing head applies a press-in load to the test piece to carry out micro-nano indentation testing, so as to acquire a load-depth curve of the material indentation test. The slope atthe top of the curve of an unload part of the load-depth curve is acquired, and the elastoplastic theory and an Olive-Pharr method are used to quantitatively evaluate the influence of the perpendicularity of the flat pressing head on the indentation contact area. The correction calculation method for the mechanical property parameters of the perpendicularity of the flat pressing head to the testedmaterial is acquired. According to the invention, the perpendicularity of the flat pressing head in the indentation test is measured; the mechanical property parameters of the material in the indentation test are corrected and calibrated; and the quantitative evaluation method is provided for quantitatively evaluating the influence of the perpendicularity of the pressing head in the indentation test and correcting an indentation test result.

Description

technical field [0001] The invention relates to the field of material mechanical performance testing, in particular to a method for correcting the verticality of a flat indenter to the mechanical parameters of an indentation test material. It is a test method suitable for micro-nano indentation test to determine the mechanical performance parameters of materials. The invention can correct the measurement error of the material mechanical property parameters caused by the installation of the indenter indenter and other factors in the indentation test, so as to satisfy the hardness and Young’s parameters of the tested material. The demand for accurate measurement of mechanical performance parameters such as modulus. Background technique [0002] With the continuous development of precision / ultra-precision micro-nano manufacturing and precision detection technology, various micro-nano systems and micro-nano structure devices emerge in an endless stream. Correspondingly, the res...

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Problems solved by technology

Influencing factors mainly include environmental factors such as temperature, noise, vibration, humidity, indenter geometry, tip size, hardness and other indenter factors, as well as size effects, surface roughness, depressions and protrusions, residual stress and other test pieces of the tested piece. Factors, especially in the test process, due to the processing defects of the indenter, the installation error of the instrument, the flexibility of the instrument frame, the uniformity of the thickness of the tested piece, the consistency of the material distribution of the tested piece, etc. The verticality factor that is not vertically pressed into the surface of the test piece has a particularly significant impact on the results of the micro-nano indentation test. The calculated mechanical property parameters of the material are biased

At present, most researchers at home and abroad use simulation calculation methods to study the verticality in indentation test and its influence on the test results, and most of them only involve the glass indenter. Research Report on Indentation Test of Indenter

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