挤压铝合金表面再结晶数值量化分析

铝合金挤压及热处理过程中,产品表面金属组织的再结晶现象是影响生产效率和产品质量较为重要的因素。通过模具优化设计和生产工艺参数优化设计,对包括挤压比、挤压轴速度、坯料温度、挤压模式等在内的参数调整,可以有效控制产品表面及内部组织的再结晶现象。为解决优化设计过程中普遍存在的成本较高和周期较长等制约因素,通过数值模拟及基于统计学原理的实验设计技术,包括FEM技术、材料微观冶金建模技术,基于统计学原理的Taguchi实验及结果分析相结合的方法;FEM结合冶金模型二次开发,可以较为精确的模拟挤压过程中金属组织结构的演化;结合实验设计(Design of Experiment,DOE),如Taguchi等方法,可以量化分析出主要的工艺参数对于产品表面再结晶的影响。该研究为工艺优化设计提供了有力的工具。

Individual influence of forming parameters on surface recrystallization during aluminium extrusion

It is well known that during the extrusion of aluminium alloys,the operating parameters(extrusion ratio,ram speed,billet temperature and extrusion mode) influence subsequent surface recrystallization.Research had been made on the influence of some parameters but the individual influence of each parameter is not clear.The respective influence of the major parameters was studied by the use of the Taguchi method combined with FEM simulation.The Taguchi method was adopted to establish the sequence of the simulations and to analyse the influence of each parameter.The following simulation results,including sub-grain size,volume fraction recrystallization and recrystallized grain size are obtainable by using this metallurgical model:The calculated results are in reasonable agreement with the experimental data now available.