基于单熔道试验的选区激光熔化成形TC4钛合金表面成形质量研究

基于单熔道试验的基础参数,设计了单熔道、多熔道搭接、单层成形搭接试验,研究了钛合金3D打印过程中点到线、线到面、面到体的成形工艺及表面成形质量。首先通过单熔道试验确定了成形质量较好的工艺参数区间,并依此参数进行了多熔道搭接和单层成形试验,分别研究了成形表面质量和工艺参数对成形精度的影响,对层间的搭接形貌和缺陷展开了分析,进一步优化了工艺参数;打印了成形块体,对前面的分析结论进行了验证。试验结果表明:采用高功率、低扫描线间距,适当降低曝光时间可有效提高表面成形质量,降低Sa值,Sa值最低可以达到3.85μm;扫描线功率显著影响成形精度尤其是成形厚度,采用高功率、较低的曝光时间可以减少成形后的厚度误差,误差最小可以达到3.96‰。

Study on surface quality of TC4 alloy formed by selective laser melting based on single-track experiment

Based on the single-track experiment parameters,designed the single-track,multi-track single-layer overlap,and single-track multi-layer experiments,this paper studies the forming technology and surface forming quality of point-to-line,line-to-surface,and surface-to-body in 3 D printing of titanium alloy. We first identified the range of process parameters with better forming quality was determined through single-melt channel tests,and multimelt channel lap and single-layer forming tests were carried out based on this parameter. The effects of forming surface quality and process parameters on forming accuracy were studied. The lap morphology and defects between layers were analysed,and the process parameters were further optimized;the forming block was printed to verify the previous analysis conclusions. The experimental results show that: high power,low hatch space,appropriate reduction of exposure time can effectively improve the surface forming quality and reduce the Sa value,the lowest Sa value can reach 3. 85μm;laser power significantly affects forming accuracy,especially forming thickness,high power and low exposure time can reduce the thickness error after forming,and the minimum error can reach 3. 96 ‰,the block with better surface forming quality has smaller final thickness error.