Method for testing mechanical property of superhard diamond film

Abstract

The invention discloses a method for testing the mechanical property of a superhard diamond film. The testing method comprises the following steps of: measuring a hardness and an elastic modulus of the diamond film by a micron indentation method; continuously applying a load in the range of a plurality of N to thousands of N to the diamond film by an automatic loading mechanism; applying the continuous load to the surface of the diamond film by an artificial diamond indenter and controlling the indentation depth in the range of one tenth to one fifteenth of the film thickness; processing by adisplacement sensor and a computer to obtain a load-depth curve of a material; obtaining a load-depth curve in the unloading process according to a preset unloading rate; and calculating two groups of data to obtain the elastic modulus and the hardness of the material. In the invention, the hardness and the elastic modulus of the diamond film are measured by the micron indentation method; and thecheap diamond pressure head is utilized to replace an expansion diamond film pressure needle, so that the experiment cost is reduced, the experiment error is reduced, and the measurement requirementson the hardness, the elastic modulus and the film-substrate cohesion of the diamond film can be met.

Description

technical field [0001] The present invention relates to a technique for measuring and evaluating the mechanical properties of a superhard diamond film, in particular to a method for testing the mechanical properties of a superhard diamond film, especially a method with a thickness ranging from several micrometers (μm) to hundreds of micrometers (μm). ) diamond film, the mechanical properties include film hardness and elastic modulus, and the bonding force between the film and the substrate. Background technique [0002] In recent years, the use of plasma enhanced chemical vapor deposition (PECVD, Plasma Enhanced Chemical Vapor Deposition) and other methods to prepare superhard diamond film materials has achieved rapid development, and the preparation and application of diamond films have become a new field in the field of thin film materials. important research directions. The mechanical properties of the diamond film, including hardness, elastic modulus, and the bonding fo...

AI Technical Summary

Problems solved by technology

Synthetic diamond has such a characteristic that it has a strong bearing capacity in the vertical direction, but a weak bearing capacity in the horizontal direction. Therefore, the problem of measuring the bonding force between the diamond film substrates by the scratch method is to gradually increase the load on the diamond tip and scratch the diamond film in the horizontal direction. surface, it is easy to cause abnormal wear and cracking of the indenter, resulting in inaccurate test results and poor test repeatability

[0007] Another bonding force measurement method is the foreign fixed load indentation method. A constant load is applied on the surface of the film through a pressure ball, and a qualitative evaluation is made after comparing the indentation photo with the standard photo. This method cannot be quantitative. Characterize the bonding force between diamond film and substrate

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