搅拌摩擦加工对选区激光熔化AlSi10Mg合金纳米力学行为的影响

Effect of friction stir processing on nanomechanical behavior of AlSi10Mg alloy by selective laser melting

使用搅拌摩擦加工(FSP)技术对选区激光熔化制备的AlSi10Mg合金进行表面改性,采用循环纳米压痕技术研究了循环载荷下FSP对材料的纳米力学行为的影响。结果表明,FSP可以显著改善SLM-AlSi10Mg合金的组织均匀性,使得晶粒转变为更为细小的等轴晶晶粒,降低其弹性模量和接触硬度。随着循环次数的增加,材料的接触硬度不断降低,但弹性模量基本不变,主要是由于尺度效应引起的。与BM试样相比,FSP试样的塑性抗力H_(T)显著降低,在循环过程中塑性应变能普遍偏高。FSP试样的滞后回线面积和塑性变形区远大于BM试样,进一步表明FSP可以改善材料的塑性。

Friction stir processing(FSP) technology was used to modify the surface of AlSi10 Mg alloy prepared by selective laser melting(SLM).The effect of FSP on the nanomechanical behavior of material under cyclic loading was investigated by cyclic nanoindentation technique.The results show that FSP can significantly improve the microstructure uniformity of SLM-AlSi10 Mg alloy,which changes the grain into finer equiaxed grains and reduces the elastic modulus and contact hardness.With the increase of the number of cycles,the contact hardness of material decreases,but the elastic modulus remains unchanged,which is mainly caused by the size effect.Compared with BM specimen,the plastic resistance H_(T) of FSP specimen decreases significantly,and the plastic strain energy of FSP specimen is generally higher during the cycle.The hysteresis loop area and plastic deformation zone of FSP sample are much larger than that of BM specimen,which further indicates that FSP can improve the plasticity of material.