Microstructure and properties of TiCp/M2 powder metallurgical high speed steel
LONG Xuehu1, TENG Hao2, LI Zhiyou1
1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China; 2. College of Mechanical Engineering, University of South China, Hengyang 421001, China
Abstract：High-energy ball milled M2 high speed steel powders reinforced with 6%Mo2C and 3%-12%TiC have been cold-pressed and subsequently sintered at 1 030-1 240 ℃ under vacuum to obtain TiC particle reinforced M2 powder high speed steel composites (TiCP/M2). The phase, microstructure and properties of sintered TiCp/M2 high speed steel were tested and analyzed by X-ray diffractometer, scanning electron microscopy and universal material testing machine. The results show that the mixed powders have higher sintering activity, and all samples can be fully densified when sintered below 1 220 ℃. The addition of TiC will hinder the densification process of high speed steel. Compared with 3%TiCp/M2, the sintering temperature of 12%TiCp/M2 increases by about 40 K. TiC can promote the formation of MC carbides. With the increase of sintering temperature, the volume fraction of TiC decreases, while the size and volume fraction of MC carbides increase. The hardness of TiCP/M2 high speed steel increases with increasing TiC content. At the optimum sintering temperature, the hardness (HRC) increases from 58.3 to 62.1 with the increase of TiC content from 3% to 12%, respectively. The bending strength of high speed steel increases first and then decreases with increasing TiC content. The highest bending strength of 9%TiC/M2 is 2 358 MPa. The addition of TiC can widen the sintering temperature range of M2 high speed steel to a certain extent.
龙学湖, 滕浩, 李志友. TiCp/M2粉末高速钢的显微组织与性能[J]. 粉末冶金材料科学与工程, 2019, 24(5): 430-436.
LONG Xuehu, TENG Hao, LI Zhiyou. Microstructure and properties of TiCp/M2 powder metallurgical high speed steel. Materials Science and Engineering of Powder Metallurgy, 2019, 24(5): 430-436.
[1] 邓玉昆, 陈景榕, 王世章. 高速工具钢[M]. 北京: 冶金工业出版社, 2002: 1-16. DENG Yukun, CHEN Jingrong, WANG Shizhang.High Speed Tool Steel[M]. Beijing: Metallurgical Industry Press, 2002: 1-16. [2] 闫建新, 李在元. 粉末高速钢的研究进展[J]. 硬质合金, 2010, 27(5): 316-320. YAN Jianxin, LI Zaiyuan.Development of PM high speed steel[J]. Cemented Carbide, 2010, 27(5): 316-320. [3] BOLTON J D, GANT A J.Microstructural development and sintering kinetics in ceramic reinforced high speed steel metal matrix composites[J]. Powder Metallurgy, 1997, 40(2): 143-151. [4] LIU Z Y, LOH N H, KHOR K A, et al.Mechanical alloying of TiC/M2 high speed steel composite powders and sintering investigation[J]. Materials Science & Engineering A, 2001, 311(1): 13-21. [5] 付文超, 肖志瑜, 李小峰, 等. 放电等离子烧结制备TiCp/M2高速钢复合材料[J]. 粉末冶金材料科学与工程, 2015, 21(2): 194-199. FU Wenchao, XIAO Zhiyu, LI Xiaofeng, et al.Preparation of TiCp/M2 composite by spark plasma sintering[J]. Materials Science and Engineering of Powder Metallurgy, 2015, 21(2): 194-199. [6] BADGER J.Grindability of conventionally produced and powder-metallurgy high-speed steel[J]. CIRP Annals -Manufacturing Technology, 2007, 56(1): 353-356. [7] COSTA F A D, SILVA A G P D, FILHO F A, et al. Solid state sintering of a W-25wt% Ag powder prepared by high energy milling[J]. International Journal of Refractory Metals & Hard Materials, 2008, 26(4): 318-323. [8] KONG L B, MA J, ZHU W, et al.Highly enhanced sinterability of commercial PZT powders by high-energy ball milling[J]. Materials Letters, 2000, 46(5): 274-280. [9] MALEWAR R, KUMAR K S, MURTY B S, et al.On sinterability of nanostructured W produced by high-energy ball milling[J]. Journal of Materials Research, 2007, 22(5): 1200-1206. [10] RONG S F, LIU C, GUO J W, et al. The influence of hadifield steel-bonded TiC preparation process on microstructure and properties[J]. Advanced Materials Research, 2011, 291-294: 1825-1830. [11] 范安平, 肖平安, 李晨坤, 等. TiC基钢结硬质合金的研究现状[J]. 粉末冶金技术, 2013, 31(4): 298-303. FAN Anping, XIAO Ping’an, LI Chenkun, et al.Research situation of TiC-based steel bonded carbide[J]. Powder Metallurgy Technology, 2013, 31(4): 298-303. [12] 范景莲, 黄伯云, 汪登龙. PCA对机械合金化纳米粉末的SEM结构与成分分布均匀性的影响[J]. 中国有色金属学报, 2003, 13(1): 116-121. FAN Jinglian, HUANG Boyun, WANG Denglong.Effect of PCA on SEM structure and composition distribution uniformity of mechanically alloyed nanopowders[J]. The Chinese Journal of Nonferrous Metals, 2003, 13(1): 116-121. [13] WRIGHT C S, OGEL B.Supersolidus sintering of high speed steels: Part 1: Sintering of molybdenum based alloys[J]. Powder Metallurgy, 1993, 36(3): 213-219. [14] LIU Z Y, LOH N H, KHOR K A, et al.Microstructure evolution during sintering of injection molded M2 high speed steel[J]. Materials Science & Engineering A, 2000, 293(1): 46-55. [15] LIU Z Y, LOH N H, KHOR K A, et al.Sintering of injection molded M2 high-speed steel[J]. Materials Letters, 2000, 45(1): 32-38. [16] VÁREZ A, LEVENFELD B, TORRALBA J M, et al. Sintering in different atmospheres of T15 and M2 high speed steels produced by a modified metal injection moulding process[J]. Materials Science & Engineering A, 2004, 366(2): 318-324. [17] ROMANO P, VELASCO F J, TORRALBA J M, et al.Processing of M2 powder metallurgy high-speed steel by means of starch consolidation[J]. Materials Science & Engineering A, 2006, 419(1): 1-7. [18] KIM K T, JEON Y C.Densification behavior and grain growth of tool steel powder under high temperature[J]. Acta Materialia, 1998, 46(16): 5745-5754. [19] ZHANG Q, YAO J, SHEN W, et al.Direct fabrication of high- performance high speed steel products enhanced by LaB6[J]. Materials & Design, 2016, 112: 469-478. [20] LIU Z Y, LOH N H, KHOR K A, et al.Sintering activation energy of powder injection molded 316L stainless steel[J]. Scripta Materialia, 2001, 44(7): 1131-1137. [21] TRABADELO V, GIMÉNEZ S, GÓMEZ-ACEBO T, et al. Critical assessment of computational thermodynamics in the alloy design of PM high speed steels[J]. Scripta Materialia, 2005, 53(3): 287-292.
2019, Vol. 24 
