Influencing Factors of Nano-indentation Test Precision

The elastic modulus of 45 steel obtained by the traditional tensile test is compared with that obtained by nano-indentation test.The results indicate that the latter is larger than the former.The main factors resulting in the experimental difference are shape of the indenter tip,surface roughness of the sample and uncertainty of zero position.Especially,random-shape of the indenter tip makes the problem is more complex at the beginning of pressing tested sample.