为了对岛式扫描策略在激光熔化沉积中的适用性进行验证, 采用正交连续扫描进行对比, 研究分析了岛式扫描对TC4成形件基底变形及性能的影响。结果表明, 相比于正交连续扫描, 随机跳转岛式扫描策略可大幅减小基底变形, 其较快的冷却速率还将细化析出的网篮α晶粒, 并抑制β晶粒的粗大生长, 但是区域交接处容易产生未熔合孔洞缺陷, 使得成形件抗拉强度与屈服强度有所提升, 但塑性有所削弱。

In order to verify the applicability of the island scanning strategy in laser melting deposition, the influence of island scanning strategy on the deformation and properties of the TC4 formed parts is studied and analyzed by comparing with orthogonal continuous scanning. The results show that compared with the orthogonal continuous scanning, the random jump island scanning strategy can greatly reduce the deformation of the substrate. The faster cooling rate will also refine the precipitated α crystal grains and inhibit the coarse growth of β crystal grains. However, the defects of incomplete fusion hole are likely to occur at regional junctions. The tensile strength and yield strength of the formed parts are enhanced, but the plasticity is weakened due to the defects.