AlSi_(10)Mg合金选区激光熔化大层厚成型及热处理工艺参数研究

Parameters of AlSi_(10)Mg Alloy Selection Laser Melting Large Thickness Forming and Heat Treatment Process

通过选择性激光熔化(selective laser melting,SLM)技术成型大层厚(60μm)AlSi_(10)Mg合金,以致密度为指标设计正交实验确定最优打印参数,对不同退火温度(200、300、400、500℃)的AlSi_(10)Mg成型件进行微观组织、物相分析和力学性能研究。结果表明:当激光功率310 W、扫描速度1450 mm/s、扫描间距95μm时,AlSi_(10)Mg成型件的致密度最高,达到99.92%;随着退火温度的升高,AlSi_(10)Mg成型件纵截面的熔池边界逐渐变得模糊,熔池边界共晶组织逐渐均匀化,X射线衍射谱中AlSi_(10)Mg原始粉末与成型件及退火后成型件对应的衍射峰有明显偏移现象;当退火温度为500℃时,退火后成型件抗拉强度伴随Si网络的断裂从355 MPa降至102 MPa,延伸率随着韧窝的增多从1.65%升高至13.25%。

The large thickness(60μm)AlSi_(10)Mg alloy was formed by selective laser melting(SLM)technology,and the optimal printing parameters were determined by orthogonal experiments with density as the index.The microstructure,phase analysis and mechanical properties of AlSi_(10)Mg alloy formed at different annealing temperatures(200,300,400,500℃)were studied.The results show that when the laser power is 310 W,the scanning speed is 1450 mm/s,and the scanning spacing is 95μm,the density of AlSi_(10)Mg alloy is the highest,reaching 99.92%.With the increase of annealing temperature,the weld pool boundary of the longitudinal section of AlSi_(10)Mg molded part gradually becomes blurred,and the eutectic structure at the weld pool boundary gradually homogenizes.In the X-ray diffraction spectrum,the diffraction peak of AlSi_(10)Mg powder corresponding to the forming part and annealed part is obviously shifted.When the annealing temperature is 500℃,the tensile strength of annealed samples decreases from 355 MPa to 102 MPa with the fracture of Si network,and the elongation rate increases from 1.65%to 13.25%with the increase of dimples.