碳化温度及抑制剂的添加对超细WC性能的影响
|
摘要
将同一批超细钨粉,分成两组进行配炭,一组不添加抑制剂,另一组添加一定量Cr_3C_2和VC,分别将两组样品分成若干小样,在真空和氢气气氛中,采用不同温度进行碳化,分析不同WC样品粉末性能,并将1 200℃碳化的WC样品制备成钴含量为8%的硬质合金,比较合金性能及金相组织的差异。实验结果表明:在氢气气氛下,钨粉更易于碳化,碳化速度更快,WC的结晶更完整;碳化阶段添加抑制剂会抑制WC晶粒的长粗,但也抑制了WC晶粒生长的完整性;提高碳化温度可以改善WC的结晶完整性,WC的粒度也会随温度的升高而增大。氢气气氛碳化的WC制备成合金后晶粒度比真空碳化的WC粗,合金晶粒的均匀性更好,异常长粗的晶粒少;在碳化阶段添加抑制剂可以更好的抑制合金晶粒的长粗,同时也抑制了WC粉末晶粒结晶的完整性,从而导致合金在液相烧结阶段晶粒的异常长粗。
The same batch of ultrafine tungsten powder was divided into two groups for carbon mixing. Inhibitors were not added into one group, and certain amounts of Cr_3C_2 and VC were added into the other group. Then the two groups of powders were divided into several samples respectively, which were carbonized in a carbide furnace under vacuum conditions and hydrogen atmosphere at different temperatures. The properties of different WC samples were analyzed, and cemented carbides with cobalt content of 8%(mass fraction) were prepared by WC samples carbonized at 1 200 ℃.Microstructure and properties of different alloy samples were compared. The experimental results show that tungsten powder is easy to be carbonized and the carbonization rate is faster, and the crystallization of tungsten carbide is more perfect in the hydrogen atmosphere. Adding inhibitor in carbonization stage can inhibit the growth of tungsten carbide grains, but also suppress the integrity of the grain growth of tungsten carbide. Increasing the carbonization temperature can improve the crystal integrity of tungsten carbide, but the grain size of tungsten carbide will increase with the increase of temperature. The grain size of the alloy prepared by WC carbonized in hydrogen atmosphere is coarser than that of WC carbonized in vacuumatmosphere, but the grain uniformity is better, and the amount of abnormal growth grain is small. Adding inhibitors in the carbonization stage can better restrain the grain size of the alloy, but also restrain the integrity of the crystal of tungsten carbide powder, which leads to the abnormal grain growth of the alloy during liquid phase sintering.
The same batch of ultrafine tungsten powder was divided into two groups for carbon mixing. Inhibitors were not added into one group, and certain amounts of Cr_3C_2 and VC were added into the other group. Then the two groups of powders were divided into several samples respectively, which were carbonized in a carbide furnace under vacuum conditions and hydrogen atmosphere at different temperatures. The properties of different WC samples were analyzed, and cemented carbides with cobalt content of 8%(mass fraction) were prepared by WC samples carbonized at 1 200 ℃.Microstructure and properties of different alloy samples were compared. The experimental results show that tungsten powder is easy to be carbonized and the carbonization rate is faster, and the crystallization of tungsten carbide is more perfect in the hydrogen atmosphere. Adding inhibitor in carbonization stage can inhibit the growth of tungsten carbide grains, but also suppress the integrity of the grain growth of tungsten carbide. Increasing the carbonization temperature can improve the crystal integrity of tungsten carbide, but the grain size of tungsten carbide will increase with the increase of temperature. The grain size of the alloy prepared by WC carbonized in hydrogen atmosphere is coarser than that of WC carbonized in vacuumatmosphere, but the grain uniformity is better, and the amount of abnormal growth grain is small. Adding inhibitors in the carbonization stage can better restrain the grain size of the alloy, but also restrain the integrity of the crystal of tungsten carbide powder, which leads to the abnormal grain growth of the alloy during liquid phase sintering.
引文
[1]吴冲浒,聂洪波,肖满斗.中国超细晶硬质合金及原料制备技术进展[J].中国材料进展,2012,31(4):39-46.Wu Chonghu,Nie Hongbo,Xiao Mandou.Development on preparation technology of ultrafine-grained cemented carbides and their raw materials in China[J].Materials China,2012,31(4):39-46.
[2]王伟,栾道成,陈庚.超细硬质合金研究进展综述[J].西华大学学报(自然科学版),2009,28(4):100-104.Wang Wei,Luan Daocheng,Chen Geng.The latest advance of ultrafine cemented carbide research[J].Journal of Xihua University(Natural Science Edition),2009,28(4):100-104.
[3]Konyashin,B.Ries.Wear damage of cemented carbides with different combinations of WC mean grain size and Co content.Part I:ASTMwear tests[J].International Journal of Refractory Metals and Hard Materials,2014,46(9):12-19.
[4]贺纪陵,徐庆荣,黎先财.超细WC制备研究进展[J].中国钨业,2008,23(6):29-32.He Jiling,Xu Qingrong,Li Xiancai.Research progress of ultra-fine WC preparation[J].China Tungsten Industry,2008,23(6):29-32.
[5]李亚军,栾道成,王正云,等.晶粒长大抑制剂对超细WC-9%Co硬质合金性能的影响[J].硬质合金,2011,28(5):288-293.Li Yajun,Luan Daocheng,Wang Zhengyun,et al.Effects of grain growth inhibitors on properties of ultra-fine WC-9%Co cemented carbides[J].Cemented Carbide,2011,28(5):288-293.
[6]Masaru Kawakami,Kozo Kitamura.Segregation layers of grain growth inhibitors at WC/WC interfaces in VC-doped submicron-grained WC-Co cemented carbides[J].International Journal of Refractory Metals and Hard Materials,2015,52(9):229-234.
[7]C H Allibert.Sintering features of cemented carbides WC-Co processed from fine powders[J].International Journal of Refractory Metals and Hard Materials,2001,19(1):53-61.
[8]G.S Upadhyaya.Materials science of cemented carbides-an overview[J].Materials&Design,2001,22(6):483-489.
[9]王文广,张贺佳,王全兆,等.碳化物抑制剂对WC-2.5%Ti C-10%Co超细晶硬质合金微观组织及力学性能的影响[J].材料研究学报,2015,29(12):882-887.Wang Wenguang,Zhang Hejia,Wang Quanzhao,et al.Effects of carbide inhibitor on microstructures and mechanical properties of ultrafine grained carbide cement WC-2.5%Ti C-10%Co[J].Chinese Journal of Materials Research,2015,29(12):882-887.
[10]羊建高,谭敦强,陈颢.硬质合金[M].长沙:中南大学出版社,2012,12.Yang Jiangao,Tan Dunqiang,Chen Hao.Cemented carbide[M].Changsha:Central South university press,2012,12.
[11]雷纯鹏,吴爱华,唐建成,等.纳米钨粉形貌结构对WC粉末性能的影响[J].稀有金属,2014,38(1):48-54.Lei Chunpeng,Wu Aihua,Tang Jiancheng,et al.Effects of morphology structure of tungsten nano-powders on properties of tungsten carbide powders[J].Chinese Journal of Rare Metals,2014,38(1):48-54.
[12]胡驰,唐子雷,吴健春.制备纳米WC的热力学分析[J].热加工工艺,2012,41(12):44-46.Hu Chi,Tang Zilei,Wu Jianchun.Thermo-dynamics analysis of synthesis nano-WC[J].Hot Working Technology,2012,41(12):44-46.
[13]徐勇,范小红.X射线衍射测试分析基础教程[M].北京:化学工业出版社,2014,1.Xu Yong,Fan Xiaohong.Tutorial of X ray diffraction test and analysis[M].Beijing:Chemical Industry Press,2014,1.
[14]李健纯.WC微观结构的研究[J].金属学报,1987,23(1):A19-A24.Li Jianchun.A study of microstructures of WC powder[J].Acta Metallurgica Sinica,1987,23(1):A19-A24.
[15]T.S Srivatsan,R Woods,M Petraroli,et al.An investigation of the influence of powder particle size on microstructure and hardness of bulk samples of tungsten carbide[J].Powder Technology,2002,122(1):54-60.
[16]Reza Mohammadi,Miao Xie,Andrew T Lech,et al.Toward Inexpensive Superhard Materials:Tungsten Tetraboride-Based Solid Solutions[J].J Am Chem Soc,2012,134(51):20660-20668.
[2]王伟,栾道成,陈庚.超细硬质合金研究进展综述[J].西华大学学报(自然科学版),2009,28(4):100-104.Wang Wei,Luan Daocheng,Chen Geng.The latest advance of ultrafine cemented carbide research[J].Journal of Xihua University(Natural Science Edition),2009,28(4):100-104.
[3]Konyashin,B.Ries.Wear damage of cemented carbides with different combinations of WC mean grain size and Co content.Part I:ASTMwear tests[J].International Journal of Refractory Metals and Hard Materials,2014,46(9):12-19.
[4]贺纪陵,徐庆荣,黎先财.超细WC制备研究进展[J].中国钨业,2008,23(6):29-32.He Jiling,Xu Qingrong,Li Xiancai.Research progress of ultra-fine WC preparation[J].China Tungsten Industry,2008,23(6):29-32.
[5]李亚军,栾道成,王正云,等.晶粒长大抑制剂对超细WC-9%Co硬质合金性能的影响[J].硬质合金,2011,28(5):288-293.Li Yajun,Luan Daocheng,Wang Zhengyun,et al.Effects of grain growth inhibitors on properties of ultra-fine WC-9%Co cemented carbides[J].Cemented Carbide,2011,28(5):288-293.
[6]Masaru Kawakami,Kozo Kitamura.Segregation layers of grain growth inhibitors at WC/WC interfaces in VC-doped submicron-grained WC-Co cemented carbides[J].International Journal of Refractory Metals and Hard Materials,2015,52(9):229-234.
[7]C H Allibert.Sintering features of cemented carbides WC-Co processed from fine powders[J].International Journal of Refractory Metals and Hard Materials,2001,19(1):53-61.
[8]G.S Upadhyaya.Materials science of cemented carbides-an overview[J].Materials&Design,2001,22(6):483-489.
[9]王文广,张贺佳,王全兆,等.碳化物抑制剂对WC-2.5%Ti C-10%Co超细晶硬质合金微观组织及力学性能的影响[J].材料研究学报,2015,29(12):882-887.Wang Wenguang,Zhang Hejia,Wang Quanzhao,et al.Effects of carbide inhibitor on microstructures and mechanical properties of ultrafine grained carbide cement WC-2.5%Ti C-10%Co[J].Chinese Journal of Materials Research,2015,29(12):882-887.
[10]羊建高,谭敦强,陈颢.硬质合金[M].长沙:中南大学出版社,2012,12.Yang Jiangao,Tan Dunqiang,Chen Hao.Cemented carbide[M].Changsha:Central South university press,2012,12.
[11]雷纯鹏,吴爱华,唐建成,等.纳米钨粉形貌结构对WC粉末性能的影响[J].稀有金属,2014,38(1):48-54.Lei Chunpeng,Wu Aihua,Tang Jiancheng,et al.Effects of morphology structure of tungsten nano-powders on properties of tungsten carbide powders[J].Chinese Journal of Rare Metals,2014,38(1):48-54.
[12]胡驰,唐子雷,吴健春.制备纳米WC的热力学分析[J].热加工工艺,2012,41(12):44-46.Hu Chi,Tang Zilei,Wu Jianchun.Thermo-dynamics analysis of synthesis nano-WC[J].Hot Working Technology,2012,41(12):44-46.
[13]徐勇,范小红.X射线衍射测试分析基础教程[M].北京:化学工业出版社,2014,1.Xu Yong,Fan Xiaohong.Tutorial of X ray diffraction test and analysis[M].Beijing:Chemical Industry Press,2014,1.
[14]李健纯.WC微观结构的研究[J].金属学报,1987,23(1):A19-A24.Li Jianchun.A study of microstructures of WC powder[J].Acta Metallurgica Sinica,1987,23(1):A19-A24.
[15]T.S Srivatsan,R Woods,M Petraroli,et al.An investigation of the influence of powder particle size on microstructure and hardness of bulk samples of tungsten carbide[J].Powder Technology,2002,122(1):54-60.
[16]Reza Mohammadi,Miao Xie,Andrew T Lech,et al.Toward Inexpensive Superhard Materials:Tungsten Tetraboride-Based Solid Solutions[J].J Am Chem Soc,2012,134(51):20660-20668.