喷丸强化纯铝表面完整性的数值研究

为数值研究喷丸强化纯铝的表面完整性,发展一种新型的喷丸强化有限元模型,模拟多弹丸连续冲击材料表面的过程,弹丸冲击形成的凹坑在受喷表面上呈圆周分布。建立一条圆周路径,计算在该圆周路径上的喷丸覆盖率,通过改变弹丸个数分析在不同喷丸覆盖率下沿受喷表面圆周路径分布的表面形貌、粗糙度、残余应力、加工硬化和晶粒细化。结果表明:随着喷丸覆盖率的增大,受喷表面粗糙度、残余压应力、表面硬化程度和晶粒细化程度都随之增大,但达到完全喷丸覆盖率后,受喷表面粗糙度、残余压应力、表面硬化和晶粒细化增大的幅度逐渐减小,逐渐趋于稳定,该变化趋势与材料表面等效塑性应变的演化相一致。

Numerical Study on Surface Integrity of Shot-Peened Aluminum

The surface integrity of shot-peened aluminum was numerically studied.A new finite element model of shot peening was developed,in which the indentations produced by multiple shot impacts are distributed uniformly on a circle within the shot-peened surface.The shot peening coverage was calculated by creating a circular path.Under the different shot peening coverage,the circular path-distributed surface morphology,roughness,residual stress,work hardening and grain refinement were investigated.The results show that,with the increase of shot peening coverage,the surface roughness,residual compressive stress,work hardening degree and grain-refinement degree increase,but the increments gradually decrease and present the saturate tendency after exceeding the full coverage,which are in accord with the evolution of surface equivalent plastic strain induced by multiple shot impacts.