Ti-6Al-4V电弧熔丝增材轧制复合制造的有限元模拟

Finite Element Simulation of Hybrid Manufacturing of Ti-6Al-4V by Wire Arc Additive Manufacturing and Rolling

摘要:

增材制造过程中由于在凝固及随后的冷却阶段易产生残余应力,从而影响部件的成形和使用。在增材过程中引入轧制工序,可望降低宏观残余应力,从而降低部件的变形。本文通过建立Ti-6Al-4V钛合金电弧熔丝增材与层间轧制复合成形过程的有限元模型,研究圆柱形轧辊条件下不同压下量对部件温度、应力、应变及残余应力分布的影响规律。结果表明,层间轧制可显著降低沉积层金属中的残余宏观应力；同时降低对基板的整体应力。采用圆柱形轧辊并增加压下量可显著降低宏观残余应力,还可以通过塑性变形改变材料的微观组织,提高材料性能,为复合增材工艺的优化指明了方向。

Abstract:

In Wire Arc Additive Manufacturing (WAAM), residual stress is easily generated during solidification and subsequent cooling, which affects the formation and use of the components. In this paper, finite element simulations are carried out to investitgate the influence of roller reductions on the temperature, stress, strain and residual stress distribution in components during the hybrid forming of Ti-6Al-4V alloy by WAAM and interlayer rolling. The results show that interlayer rolling reduce the residual macroscopic stress significantly in the deposited metal, and at the same time reduce the overall stress on the substrate. Increasing reduction can reduce significantly the macroscopic residual stresses and distorsion of the components. The microstructure of the material can be changed dramatically by the plastic deformation after rolling, which lead to a new route for the optimization of the microstructure during additive manufcturing.