TC11钛合金叶片上亮条和暗条的性质及控制

Characteristic and Control of Bright and Dark Striations in TC11 Titanium Alloy Blades

对TC11钛合金叶片上发现的亮条和暗条的性质进行了分析,并提出了减少或消除亮条和暗条的解决措施。结果表明,亮条一般为富钛偏析或富铝偏析;暗条一般为叶片锻造时形成的应变线,也有情况下为富β稳定化元素偏析。叶片上的偏析性质的亮条和暗条一般与钛合金铸锭熔炼过程有关,为了消除或减少偏析,应加强配料选择、电极制备、合金熔炼等工艺的控制,并注重各工序间的质量检验。叶片上属于锻造应变线的暗条可通过调整叶片锻造和热处理工艺参数来减轻或消除。

The characteristic of bright and dark striations in TC11 titanium alloy was analyzed. Meanwhile, the solution to decrease or eliminate the bright and dark striations was recommended. The results show that most of the bright striations are titanium-rich segregation or aluminum-rich segregation. In other instance, the bright striation may be interstitial elements richened segregation. The dark striations are the strain trace formed during forging of the blades or β phase stabilized elements richened segregation. The forming reason of the compositional segregations related bright and dark striations is mainly resulted from the melting process of the titanium alloy ingots. To decrease or eliminate the compositional segregation, raw materials selection, electrode preparation, melting process must be controlled properly, and the quality inspection must be done at some important procedures. The forging strain trace related dark striations can be decreased or eliminated by optimizing the practice parameters in forging and heat treatment procedures.