TiB_2-Cu复合材料热冲击损伤行为的数值模拟

Numerical Simulation on Thermal Shock Damage Behavior of TiB_2-Cu Composite via Combustion Synthesis

利用等离子电弧加热器结合数值模拟,考察了燃烧合成制备的TiB2-Cu金属陶瓷复合材料热冲击损伤行为;通过热物理性能实验数据,模拟了材料在高温环境中非均匀热传输边界条件作用下瞬态温度场和热应力场的分布。结果表明:材料中心位置处于压应力,并且沿径向递减;当越过电弧加热区,压应力逐渐转变为拉应力,并且最大拉应力处于试样周边区域;在热冲击条件下的损伤行为是热裂纹产生于试样边缘,然后沿径向中心区域扩展;等离子电弧加热实验也证实了理论模型的合理性。

The thermal shock behavior of TiB2- Cu composite by combustion synthesis was investigated using plasma arc heating and numerical simulation. The transient temperalure field and thermal stress fields affected by inhomogeneous boundary conditions of heat transfer in high temperature were simulated and analyzed based on the thermal physical data with ANSYS commercial software. The results reveal that the maximum compression stresses are generated at center of sample and decreased along radius. The compression stresses transform to tensile stresses when the arc beam gets across the heating area, and the largest tensile stress takes place in the edge of the specimen. The crack may initiate in the edge of the sample, and then properly propagates to the position of center in the direction of radius. The experiment of plasma arc heating also favor and approve the rationality nf theoretical model.