Characterization method of mechanical properties of elastic-plastic graded modification layer on metal surface

Abstract

The invention discloses a characterization method of mechanical properties of an elastic-plastic graded modification layer on a metal surface and belongs to the field of characterization of properties of modification layers on metal surfaces. According to the method, a plasma surface alloying method is adopted for a polished metal base material, infiltration elements are selected reasonably, and the elastic-plastic graded modification layer is formed on the surface of the polished metal base material. Butt bonding, sample inlaying and polishing treatment are performed on cut and prepared sample cross sections. The modification layer is divided into multiple sub-layers according to the thickness of the modification layer and the indentation contact radius for a nano-indentation test. Inverse analysis calculation is performed on a load-displacement curve obtained through test of each sub-layer with ANSYS v10.0 finite element software, and the elastic-plastic property parameter of each sub-layer is obtained. Mechanical property parameters of all the sub-layers are numerically fitted, so that mechanical property parameters of all points in the thickness direction of the elastic-plastic graded modification layer on the metal surface are obtained quantitatively. The method is easy to operate, besides, the matrix effect is eliminated, and the result is accurate and reliable.

Description

technical field [0001] The invention relates to a method for characterizing the mechanical properties of a metal surface elastic-plastic gradient modified layer, and belongs to the field of mechanical property characterization of the metal surface modified layer. Background technique [0002] Metal surface modification can effectively improve various performances such as wear resistance, deformation, fatigue, and corrosion of metal surfaces. Therefore, metal surface modification has been widely used in various industries since ancient times. Compared with the homogeneous modified layer, the gradient modified layer has two advantages: one is that there is no obvious interface problem, which can effectively avoid the spalling failure caused by interface weakening; the other is that it has better deformation coordination ability and can withstand High static / dynamic contact load has important application value for soft metal materials such as titanium alloy. [0003] At prese...

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Problems solved by technology

In Analysis of instrumented indentation test data for functionally graded materials, Surface & Coatings Technology, 2003, 168(2): 136-141 and Mechanics of indentation of plastically graded materials-I: Analysis, Journal of the Mechanics and Physics of Solids, 2008, 56(1):157-171. It is mentioned to establish the general constitutive equation of the gradient modified layer, but the mathematical simplification is too much, and the derivation is cumbersome, it is not applicable to the elastic-plastic gradient modified layer, only applicable to elastic Materials with obvious gradient effect or plastic gradient effect

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