金属模具电磁热裂纹止裂研究的新进展

Advance of research on crack arrest in metal die by using electromagnetic heating

综述了在理论分析、数值模拟和实验研究方面,关于利用电磁热效应实现金属模具裂纹止裂研究的最新进展,所得结论可以为工程实际问题的解决提供指导。采用复变函数方法,建立了金属模具电磁热效应空间裂纹止裂的理论分析模型,求解了通电瞬间裂尖附近的热源功率、温度场和热应力场;采用电、热和机械场三场顺次耦合的有限元分析方法建立了金属模具中平面、空间裂纹电磁热裂纹止裂的数值分析模型;采用自制的ZL-1型和改进型ZL-2超强脉冲电流发生装置实现了金属模具试件中电磁热裂纹止裂;研究了各种实际金属模具中裂纹电磁热止裂后的修复。为将电磁热裂纹止裂应用到金属模具裂纹止裂中进行了基础研究工作。

Summarized the advance of research on the crack arrest in a metal die by using electromagnetic heating from theoretical analysis,numerical simulation and experimental.The results obtained can provide the theoretical basis for solving practical problems. The complex function method is used as a basis for the theoretical model of the space crack prevention in metal dies using electromagnetic heating. The heat source power, temperature and stress fields are studied around the crack tip in metal dies with half-embedding round the crack when the pulse current is switch on. The finite element coupled field theory is used as a foundation for the method of plane and space crack prevention in metal dies when a super-density pulse current is switched on. Thermal-electricity - mechanical orderly coupled process is exercised in numerical simulation. The experimental has been conducted on pulse current generators （model ZL-1 and ZL-2） developed by the authors. Many kinds of materials for metal dies are studied such as plastic die steel, cold-applied die steel and hot applied die steel. The techniques for repair are studied after crack arrest in metal dies using electromagnetic heating. The basic experimental research is finished for crack arrest in metal dies using electromagnetic heating.