预合金粉为黏结剂的TiC钢结硬质合金组织演变与强韧性研究  

Research on Microstructure Evolution and Strength-toughness Properties of TiC Steel-bonded Carbide with Pre-alloyed Powder as Binder

作　　者：李国平[1,2] 罗丰华[1] 颜练武 彭英彪 李建国 Li Guoping;Luo Fenghua;Yan Lianwu;Peng Yingbiao;Li Jianguo(State Key Laboratory of Powder Metallurgy,Central South University,Changsha Hunan 410083,China;Laiwu Vocational and Technical College Laiwu Shandong 271100,China;College of Metallurgy and Material Engineering,Hunan University of Technology,Zhuzhou Hunan 412007,China;Shandong Rongjin Powder Science and Technology Co.,Ltd.,Laiwu Shandong 271100,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]莱芜职业技术学院,山东莱芜271100 [3]湖南工业大学冶金与材料工程学院,湖南株洲412007 [4]山东融金粉末科技有限公司,山东莱芜271100

出　　处：《硬质合金》2018年第2期108-115,共8页Cemented Carbides

基　　金：2014年山东省科技发展计划项目(No:2014GGX102015)

摘　　要：采用水雾化法制备了Fe-xMo(x=1.5、3.0、4.5、6.0)预合金粉,以这种粉末为黏结剂,采用粉末冶金工艺制备了TiC高锰钢钢结硬质合金。研究了Fe-Mo粉的Mo含量对烧结合金组织演变和强韧性的影响。对球磨粉的粒度检验表明,由于Mo元素的合金化作用,提高了黏结相粉末的硬度,因此,可以将混合粉末破碎得更加细小,提高了粉末的活性,有助于合金的烧结和致密化。合金的组织观察表明,采用Fe-Mo预合金粉为黏结剂可以显著细化和球化TiC硬质相,组织均匀。当合金中Mo的质量分数为1.15%(即Fe-3.0Mo为黏结剂)时,合金的组织最好,强度和韧性达到最大值,分别为2 296 MPa和12.67 J/cm^2。之后,合金的晶粒尺寸随着Mo含量的增加而增大,强韧性逐渐降低。因此,采用成分合适的Fe-Mo预合金粉为黏结剂可以显著提高合金的强韧性。Pre-alloyed Fe-xMo（x=1.5, 3.0, 4.5, 6.0） powder was prepared by the water atomization method. With the obtained powder as binder, high manganese TiC steel-bonded carbides were prepared by the conventional powder metallurgy techniques. The effects of Mo content of the Fe-Mo powder on the microstructure evolution and strength-toughness properties are studied. Through the tests of particle size of the ball milled powder, the results showed that the increase in the hardness of the binder phase powder can be attributed to the alloying function of the Mo element. Therefore, it is possible to have the mixed powder crushed into finer particles to improve the activity of the powder, which is beneficial for the densification and sintering of cemented carbides. It is shown from the observation of alloy microstructures that Fe-Mo pre-alloyed powder as binder can refine and spheroidize the TiC hard phase remarkably, thus producing a homogeneous structure. When the Mo mass fraction of the alloy is 1.15%（namely Fe-3.0Mo as binder）, the microstructure is the best, and the transverse rupture strength（TRS） and toughness reach the maximum, 2 296 MPa and 12.76 J/cm^2 respectively. Subsequently, the particle size of the alloy increases with the increase of Mo content, but the strength and toughness decrease. In conclusion, the strength and toughness of the alloy can be improved significantly by use of appropriate Fe-Mo pre-alloyed powder as binder.

关 键 词：TIC 钢结硬质合金 预合金黏结剂 组织演变 强韧性 

分 类 号：TF125.3[冶金工程—粉末冶金]