线性摩擦焊接过程三维热力耦合有限元分析

采用热力耦合有限元方法，建立了线性摩擦焊接过程三维弹塑性有限元计算模型，综合考虑了异种材料线性摩擦焊接成型过程的几何非线性、材料非线性和摩擦界面接触非经性行为，着重分析了摩擦焊接过程中的不同产热机制及转化规律，直接由焊件材料的性能参数及设定的焊接规范参数对线性摩擦焊接过程的焊接参数、物理参量场的变化规律进行了数值模拟，得到了线性摩擦焊接过程中的温度场和应力场变化规律。为整体叶盘线笥摩擦焊接制造技术的发展提供理论基础。

On Exploring Linear Friction Welding of Blade to Disk of Aeroengine Rotor

Blisk (integrally bladed disk) is a key technology for improving performance of aeroengine. When the blade material is single-crystal Chinese DD3 superalloy and disk material is powder metallurgy Chinese FGH95 superalloy (nearly equivalent to U.S. Ren(?)95), there are unanswered questions that need to be explored about linear friction welding (LFW) of blisk. Theoretical exploration requires: (1) three-dimensional elastic-plastic FEM (Finite Element Method); (2) consideration of coupling of temperature and stress fields. We take into account geometric nonlinearity, material nonlinearity and contact nonlinearity between different materials during linear friction welding (LFW). Different from usual theoretical simulation, we simulate directly from the parameters of the welded materials and the welding conditions. We discuss in detail in section 3 the following simulations results: (1) the variations of temperature and shearing stress at the interface of blade and disk with time (Fig. 2); (2) temperature field as shown in Fig. 4; (3) stress field as shown in Fig. 5. We summarize our discussion of temperature field as follows: at the initial stage of friction, the heating of friction surface is characterized by high heating speed, high temperature and high temperature gradient; the peak temperature appears at the beginning of brake stage (8s in Fig. 2); the highest heating power and temperature of the interface appear at its center; the temperature fields of blade and disk away from the interface are different. We summarize our discussion of stress field as follows; at the initial stage of friction, the pressure between the blade and the disk is generally uniformly distributed;. when plastic deformation occurs in the neighborhood of the interface, the friction workpiece (disk and blade) has three high stress zones and two low stress zones in the neighborhood of the interface and the normal pressure between the blade and disk is approximately a paraboloid; during the last phase of friction and forging, the stresses at the perimeter of interface become tensile, and the deformation is greater on the Ren(?)95 (disk) side. These simulation results are a promising first step towards application of LFW to blisk manufacture.