TiC颗粒对铸态球墨铸铁组织和力学性能的影响  

Effect of TiC particles on microstructure and mechanical properties of as cast ductile iron

作　　者：王金国 任帅[1,2] 闫瑞芳 黄恺 王志强 WANG Jin-guo;REN Shuai;YAN Rui-fang;HUANG Kai;WANG Zhi-qiang(Key Laboratory of Automotive Materials,Ministry of Education,Jilin University,Changchun 130022,China;College of Materials Science and Engineering,Jilin University,Changchun 130022,China)

机构地区：[1]吉林大学汽车材料教育部重点实验室,长春130022 [2]吉林大学材料科学与工程学院,长春130022

出　　处：《吉林大学学报（工学版）》2019年第6期2010-2018,共9页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目（51571101）

摘　　要：采用高能球磨方法对TiC粉末进行改性,并加入到球墨铸铁熔体。使用光镜、扫描电镜、能谱仪对其组织进行分析。结果表明,球墨铸铁的石墨和基体组织均得到改善。一部分TiC颗粒作为石墨异质核心,促进了石墨形核,使石墨球数目增加40.5%,石墨球尺寸细化,铁素体含量升高了4.5%,球化率提高了9.1%。另一部分进入基体的TiC颗粒,不仅改变了周围的渗碳体形貌,甚至形成独特的“珠光体团”结构;而且能阻碍晶界运动进而细化铁素体晶粒。采用拉伸试验机和冲击试验机对铸态球墨铸铁进行力学性能测试,结果表明,外加少量TiC颗粒使球墨铸铁的断裂总伸长率提高了19.1%,室温冲击韧性提高了31.1%,低温(-20℃)冲击韧性提高了21.8%。TiC powder was modified by high-energy ball milling and added to the melt of nodular cast iron.The tissues were analyzed by optical microscopy(OM),scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS).The results show that both graphite and matrix of the ductile iron are improved.As the heterogeneous nucleation core of graphite,some TiC particles promote the nucleation of graphite,increase the number of graphite spheres by 40.5%,refine the size of graphite spheres,indirectly increase the ferrite content by 4.5%,and increase the spheroidization rate by 9.1%.On the one hand,the morphology of the surrounding cementite is changed,and even the unique“pearlite colony”structure can be formed.On the other hand,the ferrite grain is refined due to the hindrance of TiC particles to grain boundary movement.The mechanical properties of the as-cast ductile iron were tested by tensile test machine and impact test machine.The total elongation,impact toughness at room temperature and impact toughness at low temperature(-20°C)were increased by 19.1%,31.1%and 21.8%respectively by adding a small amount of TiC particles.

关 键 词：金属材料 铸态球墨铸铁 TIC颗粒 塑性 冲击韧性 

分 类 号：TG143.5[一般工业技术—材料科学与工程]