喷射成形锭材传热过程的数值模拟

Heat transfer phenomena of the spray formed billets

通过把喷射沉积形状预测模型的计算结果实时传递到二维传热方程中 ,建立起喷射沉积锭材的计算机传热模型 ,可对不同工艺条件、不同时刻的沉积锭传热行为进行计算 ,可得到任何喷射工艺条件下、任何时刻沉积坯的温度分布及任何点的冷却曲线 .并得出以下结论 :沉积衬底预热有利于减少沉积坯初始阶段的不致密区 ;改变喷射沉积工艺时 ,沉积坯的温度分布随沉积坯形状的不同发生变化 .

model of the heat transfer and solidification process of billet spray formed was made through using the effects of the form modeling in every time. Temperature fields of billets at various spray time and in various spray forming process were calculated from this numerical model. The influences on evolution of temperature fields by the principal spray forming parameters, such as spray angle, spatial distribution of melt mass flux, withdrawal speed of substrate etc., are analyzed. And conclusions are given as follow: Preheating the substrate is benefit to decrease the loosen areas at beginning of deposition. Shapes and temperature fields of the spray formed billet are effected by spray forming conditions. The results of calculating are identical with actual experiment.