烧结青铜石墨延伸率的研究

来源期刊：中南大学学报(自然科学版)1993年第5期

论文作者：张金生 高游 李晋尧 王志光

文章页码：627 - 631

关键词：烧结青铜石墨; 延伸率; 结构特征

Key words：sinfred bronze-graphite materials; specific elongation; structureal features

摘    要：讨论了烧结青铜(90/10)石墨的延伸率及其结构特征,研究了影响延伸率的因素。实验结果表明:拉伸青铜石墨不出现缩颈,而在标距范围内出现许多裂纹,试样的伸长是塑性变形和裂纹叠加的结果;降低孔隙度,孔隙球化,粗化晶粒,使延伸率得到提高;用混合粉制得的青铜石墨材料,当石墨含量小于3wt%,孔隙度不大于18%时,延伸率可大于5%。

Abstract: Specific elongations and structural features of sintered bronze-graphite materials are discussed in this paper.The factors which influenc specific elongations of the material are investigated.The results show that there is no necking phenomenon while fractures are fromed on the surface of samples during tensile tests,and that the elongation of samples results from the combination of plastic deformation and fractures.Specific elongations of the bronzegraphite materials increase with the decrease of porosity,spheroidizing of pores and coarsening of grains.Specific elongations of the materials made from mixed powders would be more than 5%,if the graphite content is less than 3 wt%,and porosity ≤18%.