硬状态金属材料表面力学性能的研究

通常用X射线衍射线的半高宽作为材料表面的强度指标.对于硬状态材料,喷丸表面的半高宽显著减小,但其屈服强度却明显提高,这一结果说明,表面屈服强度能比半高宽更好地表征材料表面的力学性能.用表面屈服强度这一新指标,可以对材料表面进行研究.实验结果表明,喷丸影响层是处于加工硬化状态,而不是处于加工软化状态,喷丸和未喷丸试样表面的屈服强度都低于整体的屈服强度,这是表面产生残余压应力的原因.

Research for mechanics characteristics of metal material surface in hard state

In general,the half width of X-ray diffraction is used as a strength index of material surface.For hard state material,Shot peening reduces the half width of the hard surfaces wholly in a large amplitude,but improves the yield strength to varying degrees.The result show that the new index of the surface yield strength reflects mechanics characteristics of material surface better than the normal used index of the half width does.Accept defeat this new index of strength with the surface,we can research the material surface.The yield strength for shot peened surface and unpeened surface low in the yield strength for bulk uniaxial tensile test,this is the reason why it makes the surface existence residual stress.