TC4钛合金板材激光切割影响研究

Influence of laser cutting on TC4 titanium alloy sheet

为确定激光切割工艺对TC4钛合金板材疲劳性能的影响,对其进行激光切割试验,从切缝表面形貌和元素成分变化、热影响区及微观组织、试件的疲劳性能及疲劳断口等方面进行了研究。结果表明:激光切割TC4钛合金的切缝表面存在大量熔融金属凝固后形成的沟槽和微观裂纹,激光切割产生的热影响区构成了疲劳源区,导致激光切割试件的疲劳寿命大幅下降;激光切割工艺应用在对零件疲劳寿命有一定要求的领域里时,应采取一定措施去除切割热影响区。

In order to investigate the influence of laser cutting on the fatigue property of TC4 titanium alloy sheet,laser cutting experiments were conducted. The morphology and element composition variation on cutting surface were investigated. The microstructure of the heat-affected zone（HAZ）induced by laser cutting was analyzed. It is found that there are a large number of microcracks generated during molten metal solidification on cutting surfaces. These microcracks and the HAZ are fatigue source which leads to the significant reduction of specimen’s fatigue life. So,it can conclude that the HAZ induced by laser cutting should be removed in some fields where fatigue properties are sensitive.