Research on the nano-hardness of single crystal aluminum

Studied the causes of the size effect phenomenon of the process of nano-hardness measurements. First of all, theoretically discussed the impact of the indenter tip radius on the hardness measurement and analysis of its impact trend, after the use of molecular dynamics method on the ends of arc with a radius of 50nm standard three pyramid indenter and the ideal shaped indenter for a different indentation depth under indentation process simulation. Theory and simulation results show that: indenter tip with a circular arc is the important reason for the produce of the nano-hardness size effect phenomenon. In nano-hardness measurements, if the constant load experiments using different ends of the radius of the indenter for testing, then the larger the indenter of the tip radius is, the greater measured hardness value. If using the same indenter, then the smaller test indenter of the indentation depth is, the greater corresponding to the indentation angle, so the measured hardness value greater.