采用化学包覆法制备WC-(8Co,2Ni)-xMo (x为质量分数,%。x=0,0.5,1.0,1.5)复合粉末,真空烧结后得到含Mo的WC-(8Co,2Ni)硬质合金。研究前驱体和复合粉末的微观形貌和物相组成,分析Mo对WC-(8Co,2Ni)硬质合金显微组织、力学性能和耐腐蚀性能的影响。结果表明,WC-(8Co,2Ni)-xMo复合粉末中的Mo均匀分布在WC颗粒表面。WC-(8Co,2Ni)-xMo硬质合金较致密,无明显孔洞,WC和黏结相无明显聚集。随Mo质量分数从0增加至1.5%,WC晶粒的平均尺寸从1.6 μm减小至1.1 μm。合金硬度(HRA)从87.3±0.1提高至88.3±0.2,抗弯强度从(2 890±27) MPa下降至(2 560±29) MPa。含Mo合金在腐蚀过程中生成低电导率的含Mo钝化膜,耐腐蚀性能明显提升。
In this work, the WC-(8Co,2Ni)-xMo (x=0, 0.5, 1.0, 1.5, mass fraction,%) composite powders were successfully prepared by chemical coating method, and then the WC-(8Co,2Ni)-xMo cemented carbides were fabricated by vacuum sintering method. The microstructure and phase composition of precursors and composite powders were studied. The effects of Mo on the microstructure, mechanical properties and corrosion resistance of WC-(8Co,2Ni) cemented carbide were investigated. The results show that the Mo in the WC-(8Co,2Ni)-xMo composite powders is uniformly distributed on the surface of the WC particles. The WC-(8Co,2Ni)-xMo cemented carbides are density, and have no obvious pores, WC and binder distribute uniformly. As the mass fraction of Mo increases from 0 to 1.5%, the average grain size of WC decreases from 1.6 μm to 1.1 μm. The hardness (HRA) of the alloy increases from (87.3±0.1) to (88.3±0.2), and the bending strength decreases from (2 890±27) MPa to (2 560±29) MPa. The low conductivity Mo-containing passivation film is formed during the corrosion process, so the corrosion resistance of the alloys is significantly improved.
[1] 唐启佳, 李重典, 王雁洁, 等. Cr3C2添加量对WC-10Co硬质合金组织与性能的影响[J]. 粉末冶金材料科学与工程, 2018, 23(5): 460-466.
TANG Qijia, LI Zhongdian, WANG Yanjie, et al.Effect of the Cr3C2 additive amount on the microstructure and properties of WC-10Co cemented carbides[J]. Materials Science and Engineering of Powder Metallurgy, 2018, 23(5): 460-466.
[2] 周书助. 硬质合金生产原理和质量控制[M]. 北京: 冶金工业出版社, 2014.
ZHOU Shuzhu.The Production Principle and Quality Control of Cemented Carbide[M]. Beijing: Metallurgical Industry Press, 2014.
[3] GARCÍA J, CIPRÉS C, BLOMQVIST A, et al. Cemented carbide microstructures: a review[J]. International Journal of Refractory Metals and Hard Materials, 2019, 80: 40-68.
[4] RAIHANUZZAMAN R M, XIE Z H, HONG S J, et al.Powder refinement, consolidation and mechanical properties of cemented carbides-an overview[J]. Powder Technology, 2014, 261: 1-13.
[5] WANG C, JIANG C, JI V, et al.Thermal stability of residual stresses and work hardening of shot peened tungsten cemented carbide[J]. Journal of Materials Processing Technology, 2017, 240: 98-103.
[6] HE R G, LI B, OU P H, et al.Effects of ultrafine WC on the densification behavior and microstructural evolution of coarse-grained WC-5Co cemented carbides[J]. Ceramics International, 2020, 46: 12852-12560.
[7] HE R G, YANG Q M, LI B, et al.Grain growth behaviour and mechanical properties of coarse-grained cemented carbides with bimodal grain size distributions[J]. Materials Science and Engineering A, 2021, 805: 140586.
[8] ZHENG Z H, LÜ J, LOI M, et al.Mechanical and tribological properties of WC incorporated Ti(C,N)-based cermets[J]. Ceramics International, 2022, 48: 10086-10095.
[9] 董帝, 王承阳. 钼合金制备工艺的研究进展[J]. 粉末冶金技术, 2017, 35(4): 304-309.
DONG Di, WANG Chengyang.Research progress on preparation technology of molybdenum alloy[J]. Powder Metallurgy Technology, 2017, 35(4): 304-309.
[10] GUO S D, BAO B, LI S Y, et al.The role of Y2O3, Cu, Mo and Mo2C additives on optimizing the corrosion resistance of WC-6Co cemented carbide in HCl and NaOH solutions[J]. Journal of Alloys and Compounds, 2020, 827: 154269.
[11] GUO S D, BAO R, YANG J G, et al.Effect of Mo and Y2O3 additions on the microstructure and properties of fine WC-Co cemented carbides fabricated by spark plasma sintering[J]. International Journal of Refractory Metals and Hard Materials, 2017, 69: 1-10.
[12] 严维, 王水龙. Mo添加对WC-6Co硬质合金组织性能的影响[J]. 稀有金属与硬质合金, 2020, 48(4): 73-78.
YAN Wei, WANG Shuilong.The effects of Mo addition on the microstructure and mechanical properties of WC-6Co cemented carbides[J]. Rare Metals and Cemented Carbides, 2020, 48(4): 73-78.
[13] HUANG J H, HUANG S G, ZHOU P, et al.Microstructure and mechanical properties of WC or Mo2C modified NbC-Ni cermets[J]. International Journal of Refractory Metals and Hard Materials, 2021, 95: 105440.
[14] BOUNHOURE V, LAY S, COINDEAU S, et al.Effect of Cr addition on solid state sintering of WC-Co alloys[J]. International Journal of Refractory Metals and Hard Materials, 2015, 52: 21-28.
[15] ZHANG Q, LIN N, HE Y.Effects of Mo additions on the corrosion behavior of WC-TiC-Ni hardmetals in acidic solutions[J]. International Journal of Refractory Metals and Hard Materials, 2013, 38: 15-25.
[16] TROSNIKOVA I Y, LOBODA P I, BILYI O I.Effect of molybdenum additions on the microstructure and properties of WC-W2C alloys[J]. Powder Metallurgy and Metal Ceramics, 2014, 53(3/4): 219-224.
[17] LIN N, WU C H, HE Y H, et al.Effect of Mo and Co additions on the microstructure and properties of WC-TiC-Ni cemented carbides[J]. International Journal of Refractory Metals and Hard Materials, 2012, 30(1): 107-113.
[18] LAUTER L, HOCHENAUER R, BUCHEGGER C, et al.Solid-state solubilities of grain-growth inhibitors in WC-Co and WC-MC-Co hardmetals[J]. Journal of Alloys and Compounds, 2016, 675: 407-415.
[19] ZHAO Z Y, LIU J W, TANG H G, et al.Effect of Mo addition on the microstructure and properties of WC-Ni-Fe hard alloys[J]. Journal of Alloys and Compounds, 2015, 646: 155-160.
[20] GHASALI E, EBADZADEH T, ALIZADEH M, et al.Mechanical and microstructural properties of WC-based cermets: a comparative study on the effect of Ni and Mo binder phases[J]. Ceramics International, 2017, 44(2): 2283-2291.
[21] KELLNER F J J, HILDEBRAND H, VIRTANEN S. Effect of WC grain size on the corrosion behavior of WC-Co based hardmetals in alkaline solutions[J]. International Journal of Refractory Metals and Hard Materials, 2009, 27(4): 806-812.
[22] SUTTHIRUANGWONG S, MORI G.Corrosion properties of Co-based cemented carbides in acidic solutions[J]. International Journal of Refractory Metals and Hard Materials, 2003, 21(3/4): 135-145.
[23] GUO S D, BAO R, LI S Y, et al, Chen H, Ye Y, The role of Y2O3, Cu, Mo and Mo2C additives on optimizing the corrosion resistance of WC-6Co cemented carbide in HCl and NaOH solutions[J], Journal of Alloys and Compounds, 2020, 827: 154269.
[24] BADAWY W A, AL-KHARAFI F M. Corrosion and passivation behaviors of molybdenum in aqueous solutions of different pH[J]. Electrochimica Acta, 1998, 44(4): 693-702.
[25] WEIDMAN M C, ESPOSITO D V, HSU Y C, et al.Comparison of electrochemical stability of transition metal carbides (WC, W2C, Mo2C) over a wide pH range[J]. Journal of Power Sources, 2012, 202(15): 11-17.
[26] ZHANG L, CHEN Y, WAN Q L, et al.Electrochemical corrosion behaviors of straight WC-Co alloys: exclusive variation in grain sizes and aggressive media[J]. International Journal of Refractory Metals and Hard Materials, 2016, 57: 70-77.
