脉冲电压对阶梯状TC4合金工件组织与性能的影响
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摘要
研究了脉冲电压对阶梯形状TC4合金工件组织和性能的影响,并初步探讨了其作用机理。结果表明:改变脉冲电压后,工件各位置组织变化明显,且当脉冲电压为700和800 V时,按照截面尺寸减小方向依次为等轴α相和晶间β相,α相和片层状β相,针状α'相。从显微硬度和电阻率变化来看,均按照截面尺寸减小方向增大,且当电压为800 V时,工件截面尺寸最小位置的显微硬度和电阻率异常增大。脉冲电压所引起的工件各部位焦耳热的差异是导致复杂阶梯状TC4合金工件组织和性能变化的根本原因。
Effect of pulse voltage on microstructure and properties of ladderlike TC4 alloy workpiece was studied and the corresponding mechanism was preliminarily analyzed. The results show that with the increasing of pulse voltage,the different position of TC4 workpiece exhibits significant changes. Furthermore,when the pulse voltage is 700 V or 800 V,the microstructure changes from equiaxial α phase and intergranular β phase,α phase and lamellar β phase to α' phase according to the reducing direction of the cross section. The microhardness and electrical resistivity trend to increase with the reducing direction of cross section. When the pulse voltage is 800 V,the microhardness and electrical resistivity at the position of minimum section is obviously increasing. The changes of the microstructure and properties of ladderlike TC4 alloy workpiece are caused the section-dependent Joule heat difference during the treatments with various pulse voltage.
Effect of pulse voltage on microstructure and properties of ladderlike TC4 alloy workpiece was studied and the corresponding mechanism was preliminarily analyzed. The results show that with the increasing of pulse voltage,the different position of TC4 workpiece exhibits significant changes. Furthermore,when the pulse voltage is 700 V or 800 V,the microstructure changes from equiaxial α phase and intergranular β phase,α phase and lamellar β phase to α' phase according to the reducing direction of the cross section. The microhardness and electrical resistivity trend to increase with the reducing direction of cross section. When the pulse voltage is 800 V,the microhardness and electrical resistivity at the position of minimum section is obviously increasing. The changes of the microstructure and properties of ladderlike TC4 alloy workpiece are caused the section-dependent Joule heat difference during the treatments with various pulse voltage.
引文
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[8]赵远云,王宝全,郭敬东.高密度脉冲电流处理改善1Cr13Mn13钢力学性能[J].金属学报,2009,45(11):1325-1329.Zhao Yuanyun,Wang Baoquan,Guo Jingdong.Improvement of mechanical properties of steel 1Cr13Mn13 by electropulsing with high density[J].Acta Metallurgica Sinica,2009,45(11):1325-1329.
[9]周亦胄,郭敬东,单以银,等.脉冲电流对低碳微合金钢力学性能的影响[J].材料研究学报,2002,16(3):243-246.Zhou Yizhou,Guo Jingdong,Shan Yiyin,et al.Effect of electropulsing on mechanical properties of a low carbon microalloy steel[J].Chinese Journal of Material Research,2002,16(3):243-246.
[10]Zhang W,Sui M L,Zhou Y Z,et al.Evolution of microstructures in materials induced by electropulsing[J].Micron,2003,34(3):189-198.
[11]Dolinsky Y,Elperin T.Thermodynamics of nucleation in currentcarrying conductors[J].Physical Review B,1994,50(1):52-60.
[12]Dolinsky Y,Elperin T.Critical currents in normal conductors[J].Journal of applied physics,1993,73(10):5283-5285.
[13]Smith W F.Stucture and Properties of Engineering Alloys[M].New York:Mc Graw-Hill,1981.