Method for evaluating thermal expansion characteristic of surface plating layer

The invention discloses a method for evaluating thermal expansion characteristics of a surface plating layer. The method comprises the following steps: constructing a function relation alpha composite (T) between a linear expansion coefficient of a composite and temperature; the composite body comprises a plating layer and a substrate material; constructing a function relationship alpha substrate (T) between the linear expansion coefficient of the substrate material and the temperature; constructing a functional relationship E coating layer (T) between the elastic modulus of the coating layer and the temperature; constructing a function relationship E substrate (T) between the elastic modulus of the substrate material and the temperature; obtaining the density rho composite of the composite body, the density rho substrate of the substrate material and the density rho plating layer of the plating layer; according to the alpha composite (T), the alpha substrate (T), the E plating layer (T), the E substrate (T),