选择性激光熔化316L不锈钢在不同成形策略下的冲击性能研究

Experimental investigation on the impact properties of 316L stainless steel specimens made by different selective laser melting forming patterns

采用选择性激光熔化（SLM）成形系统HK M250制备了垂直于Z轴的水平类型和平行于Z轴的垂直类型等多种工况的316L不锈钢冲击试样,并对试样缺口采取了SLM直接成形和机械加工成形两种方式。在室温条件下进行了316L不锈钢冲击实验,使用KEYENCE光学成像系统和扫描电镜观察了试样断口形貌,并用扫描电镜观察了不同成形截面的微观组织。实验结果表明,通过机械加工制作缺口相比于SLM直接成形缺口,其试样冲击性能更好;对于两种缺口制作方式,T（t）类型试样的冲击功明显低于H（h）类型试样,这主要是由于T（t）类型试样承载截面的内部缺陷多于H（h）类型试样,从而降低了其冲击功。

Both types of 316L stainless steel impact specimens were manufactured by selective laser melting（SLM）forming based on HK M250,forming system,including horizontal type that is perpendicular to the Z axis and vertical type that is parallel to the z axis.In addition,two patterns of sample notch forming were adopted：one is direct SLM forming and the other one is machining operation.The impact experiment of 316L stainless steel specimens was carried out at room temperature.In experiment,the fracture morphology of specimen was observed by KEYENCE optical imaging system and scanning electron microscope,and the microstructure of different forming sections was observed by scanning electron microscope.Experimental results show that the impact properties of specimen made by machining operation are better than that of specimen made by SLM direct forming.For two types of notch,the impact work of vertical type specimen is obviously lower than that of horizontal type sample,which is mainly due to the internal defects of vertical type specimen are more than those of the horizontal type,then reduce the impact work.