激光增减材交互中基体温度状态对表面质量影响研究

Influence of Matrix Temperature State on Surface Quality During Interactive Additive and Subtractive Manufacturing

为了研究增减材交互过程中基体温度状态对工件表面质量的影响,对冷却不同时间的增材工件进行铣削加工,并测试工件表面的粗糙度、表面形貌、残余应力、微观组织及硬度。在482℃基体温度下进行铣削加工时,工件表面的粗糙度约为2.226μm,表面有凹坑和凸起的缺陷,工件表面残余应力为残余拉应力,沉积层顶部硬度约为200HV。在205℃和164℃基体温度下进行铣削加工时,工件表面的粗糙度分别降低到1.192μm和0.844μm,表面形貌均由均匀的铣削纹理组成,工件表面残余应力由残余拉应力转化为残余压应力,沉积层顶部硬度分别为309HV和286HV。结果表明:随着基体温度的降低,工件表面粗糙度降低,表面缺陷减少,表面残余应力由残余拉应力转化为残余压应力,硬度增加,工件表面质量得到提高。

In order to study the influence of matrix temperature state on the surface quality of workpieces during the interaction process between additive and subtractive manufacturing,the additive workpieces with different cooling time are milled,and the surface roughness,surface morphologies,surface residual stress,surface microstructures and surface hardness of workpieces are tested.When the workpiece is milled at a matrix temperature of 482℃,its surface roughness is about 2.226μm.The surface has the defects of pits and protrusions,the residual stress is the residual tensile one,and the hardness of the top deposited layer is about 200 HV.When the workpiece is milled at matrix temperatures of 205℃and 164℃,its roughness is reduced to 1.192μm and 0.844μm,respectively.The surface morphology is composed of uniform milling textures.The surface residual stress is transformed from the residual tensile one to the residual compressive one,and the hardness of the top deposited layer is 309 HV and 286 HV,respectively.The results show that,with the decrease of matrix temperature,the surface roughness of the workpiece decreases,the surface defects are reduced,the surface residual stress is converted from the residual tensile one to the residual compressive one,the hardness increases,and the surface quality improves.