CuZnAl粉末烧结体材料挤扭成形致密化的热力耦合数值模拟
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摘要
挤扭(TE)是一种新型大塑性(SPD)变形工艺。采用体积可压缩刚粘塑性热力耦合有限元法对Cu Zn Al粉末体进行了热力耦合挤扭成形致密模拟。分析了挤扭成形致密工艺,探讨了其应力-应变场、温度场变化规律以及致密化行为。结果表明,挤扭工艺能产生较强静水压力,导致粉末多孔体材料致密化,但1道次TE的坯料横截面上各区域致密化呈不均匀性,需要多道次的挤扭成形或模具结构优化。
Twist extrusion(TE) is a new type of severe plastic deformation(SPD) technology. The densification simulation of thermo-mechanical coupling TE forming of CuZnAl powders was carried out by using the volume compressible rigid viscoplastic finite element method. The densification process of TE forming was analyzed, and the stress-strain field, the variation of temperature field and the densification behavior were discussed. The results show that TE process can produce a strong hydrostatic pressure, which leads to densification of powder porous material. But regional densification of billet cross section of one pass TE is not uniform, which needs to multi-pass twist extrusion forming or die structure optimization.
Twist extrusion(TE) is a new type of severe plastic deformation(SPD) technology. The densification simulation of thermo-mechanical coupling TE forming of CuZnAl powders was carried out by using the volume compressible rigid viscoplastic finite element method. The densification process of TE forming was analyzed, and the stress-strain field, the variation of temperature field and the densification behavior were discussed. The results show that TE process can produce a strong hydrostatic pressure, which leads to densification of powder porous material. But regional densification of billet cross section of one pass TE is not uniform, which needs to multi-pass twist extrusion forming or die structure optimization.
引文
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[2]Beygelzimer Y E,Varyukhin V N.Structural changes in metals subjected to directed or twist extrusion:mathematical simulation[J].Russian Metallurgy(Metally),2006(1):25-32.
[3]李文翔,刘曙光.ECAP对T2工业纯铜的性能影响及实验过程模拟[J].热加工工艺,2011,40(2):36-39.
[4]周明智.粉末多孔材料等通道转角挤压数值模拟及实验研究[D].合肥:合肥工业大学,2008.
[5]胡卜亮,杨西荣.纯钛连续等径通道转角挤压的有限元模拟[J].热加工工艺,2013,42(13):134-137.
[6]Shpak A P,Varyukhin V N,Tkatch V I.Nanostructured Al86Gd6Ni6Co2bulk alloy produced by twist extrusion of amorphous melt-spun ribbons[J].Materials Science and Engineering A,2006,425:172-177.
[7]李永志,薛克敏,李萍,等.多目标质量的粉末包套等通道挤扭成形致密工艺参数优化[J].机械工程学报,2012,48(6):57-63.
[8]李永志,陈爱霞.65Mn钢制大塑性变形挤扭凸模的热处理工艺改进[J].热加工工艺,2013,42(22):154-156.