金属成形热力耦合模拟与模具失效机制研究

Study on thermo-mechanical coupling simulation of metal forming and failure mechanisms of forging die

借助于Deform-3D软件对TC11钛合金齿轮盘的模锻生产过程进行了热力耦合模拟,并结合锻件生产与模具失效的统计数据,分析了锻模中3个易磨损区的主要失效机制。在1区,坯料与模具接触时间较长,随着界面传递热量的增加,模腔表面发生了软化,在高的机械压应力作用下该区域发生了粘着磨损;在3区,因氧化物颗粒和热机械疲劳裂纹产生的碎片滞留在锻模表面,并伴随着热锻过程的进行,碎片在模腔表面上发生密集流动,最终直接导致了锻模表面的磨粒磨损;而在2区,其工作条件不如3区和1区恶劣,由于锻模表面存在较大的热应力并在机械压应力的耦合作用下,锻模表面发生了热机械裂纹,但该裂纹并没有导致锻模材料的明显损耗。

The thermo-mechanical coupling simulation of TC11 titanium alloy gear disk was carried out by Deform-3 D software,and combined with the statistical data of forging production and die failure,the main failure mechanisms of forging die in three quick wearing regions were analyzed.In region 1,the contact time between the billet and die was long,with the increase of heat transfer at the interface,the surface of the die cavity was softened,and adhesive wear occurred in this area under high mechanical compression stress.In region 3,the debris caused by oxide particles and thermo-mechanical fatigue cracks was stuck on the surface of forging die,and with the hot forging process progressed,the debris flowed intensively on the surface of die cavity,which directly leaded to the abrasive wear on the surface of forging die.In region 2 where there was no such extreme conditions as in region 3 and region 1,due to the large thermal stress on the surface of forging die and the coupling of mechanical compression stress,the thermo-mechanical cracks occurred on the surface of forging die,but the cracks did not lead to the obvious loss of forging die material.