Microstructure and tribological properties of carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy
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摘要
Tungsten heavy alloys(WHAs) produced by powder technology are widely used for the mechanical manufacturing, electronic and defense components, etc.Tribological properties of these alloys need to be improved to meet the severe service conditions demanded. Carburization is a promising way to resolve this problem. In this work, microstructure and tribological properties of the carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy were investigated in comparison with those of the untreated alloy. Results show that the carburized layer consists of a porous, outer WC layer and a modified W grain layer surrounded by Fe_6W_6C and Co_6W_6C at 970℃, regardless of the carburizing time. The depth of the carburized layer linearly increases in a relatively short time and slightly increases during the subsequent period. Surface roughness increases with carburizing time. Carburization can stabilize friction coefficient and effectively improve the wear resistance of the tungsten heavy alloy due to its significantly increased hardness and non-deformability, but the porous structure in the WC layer has a negative influence on its wear resistance. The carburized layer is damaged in the porous WC layer in the form of the spalling of WC particles where there are some microcracks and micropores, accompanied with peeling due to the solid tribofilm being pushed away.
Tungsten heavy alloys(WHAs) produced by powder technology are widely used for the mechanical manufacturing, electronic and defense components, etc.Tribological properties of these alloys need to be improved to meet the severe service conditions demanded. Carburization is a promising way to resolve this problem. In this work, microstructure and tribological properties of the carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy were investigated in comparison with those of the untreated alloy. Results show that the carburized layer consists of a porous, outer WC layer and a modified W grain layer surrounded by Fe_6W_6C and Co_6W_6C at 970℃, regardless of the carburizing time. The depth of the carburized layer linearly increases in a relatively short time and slightly increases during the subsequent period. Surface roughness increases with carburizing time. Carburization can stabilize friction coefficient and effectively improve the wear resistance of the tungsten heavy alloy due to its significantly increased hardness and non-deformability, but the porous structure in the WC layer has a negative influence on its wear resistance. The carburized layer is damaged in the porous WC layer in the form of the spalling of WC particles where there are some microcracks and micropores, accompanied with peeling due to the solid tribofilm being pushed away.
Tungsten heavy alloys(WHAs) produced by powder technology are widely used for the mechanical manufacturing, electronic and defense components, etc.Tribological properties of these alloys need to be improved to meet the severe service conditions demanded. Carburization is a promising way to resolve this problem. In this work, microstructure and tribological properties of the carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy were investigated in comparison with those of the untreated alloy. Results show that the carburized layer consists of a porous, outer WC layer and a modified W grain layer surrounded by Fe_6W_6C and Co_6W_6C at 970℃, regardless of the carburizing time. The depth of the carburized layer linearly increases in a relatively short time and slightly increases during the subsequent period. Surface roughness increases with carburizing time. Carburization can stabilize friction coefficient and effectively improve the wear resistance of the tungsten heavy alloy due to its significantly increased hardness and non-deformability, but the porous structure in the WC layer has a negative influence on its wear resistance. The carburized layer is damaged in the porous WC layer in the form of the spalling of WC particles where there are some microcracks and micropores, accompanied with peeling due to the solid tribofilm being pushed away.
引文
[1]Li YY,Hu K,Li XQ,Ai X,Qu ShQ.Fine-grained 93W-5.6Ni-1.4Fe heavy alloys with enhanced performance prepared by spark plasma sintering.Mater Sci Eng A.2013;599(573):245.
[2]Hong SH,Ryu HJ.Combination of mechanical alloying and two-stage sintering of a 93W-5.6Ni-1.4Fe tungsten heavy alloy.Mater Sci Eng A.2003;344(1-2):253.
[3]Hu K,Li XQ,Qu ShG,Li YY.Spark-plasma sintering of W-5.6Ni-1.4Fe heavy alloys:densification and grain growth.Metall Mater Trans A.2013;44(2):923.
[4]Khalid FA.Characterization of in situ carbide coating of tungsten alloy.Mater Sci Eng A.2002;338(1):76.
[5]Luo A,Shin KS,Jacobson DL.High temperature tensile properties of W-Re-ThO2alloys.Mater Sci Eng A.1992;150(1):67.
[6]Hsu C,Lin S.Coalescence of tungsten grains around molybdenum grains in the presence of a liquid phase.Scr Mater.2002;46(12):869.
[7]Kemp PB,German RM.Mechanical properties of molybdenum alloyed liquid phase-sintered tungsten-based composites.Metall Mater Trans A.1995;26(8):2187.
[8]Bose A,German RM.Microstructural refinement of W-Ni-Fe heavy alloys by alloying additions.Metall Mater Trans A.1988;19(12):3100.
[9]Liu M,Cowley J.Particle/dislocation interactions in a dispersion strengthened tungsten alloy at ultrahigh temperatures.Scr Metall Mater.1993;28(3):307.
[10]Park S,Kim D,Lee S,Ryu HJ,Hong SH.Dynamic deformation behavior of an oxide-dispersed tungsten heavy alloy fabricated by mechanical alloying.Metall Mater Trans A.2001;32(8):2011.
[11]Ryu HJ,Hong SH.Fabrication and properties of mechanically alloyed oxide-dispersed tungsten heavy alloys.Mater Sci Eng A.2003;363(1-2):179.
[12]Wu GC,You Q,Wang D.Influence of the addition of lanthanum on a W-Mo-Ni-Fe heavy alloy.Int J Refract Met Hard Mater.1999;17(4):299.
[13]Zhang ZH,Wang FC,Li SK,Wang L.Deformation characteristics of the 93W-4.9Ni-2.1Fe tungsten heavy alloy deformed by hydrostatic extrusion.Mater Sci Eng A.2006;s435-436(6):632.
[14]Hong SH,Ryu HJ.Combination of mechanical alloying and two-stage sintering of a 93W-5.6Ni-1.4Fe tungsten heavy alloy.Mater Sci Eng A.2003;344(1-2):253.
[15]Upadhyaya A,Tiwari SK.Microwave sintering of W-Ni-Fe alloy.Scr Mater.2007;56(1):5.
[16]Song X,Liu X,Zhang J.Neck formation and self-adjusting mechanism of neck growth of conducting powders in spark plasma sintering.J Am Ceram Soc.2006;89(2):494.
[17]Hu K,Li XQ,Qu SG,Li YY.Effect of heating rate on densification and grain growth during spark plasma sintering of 93W-5.6Ni-1.4Fe heavy alloys.Metall Mater Trans A.2013;44(9):4323.
[18]Etsion I,Halperin G,Becker E.The effect of various surface treatments on piston pin scuffing resistance.Wear.2006;261(7-8):785.
[19]Pehlivanturk NY,Inal OT.Carburising of tungsten in a glow discharge methane plasma.In:Spalvins T,editor.Ion Nitriding.ASM International:Ohio;1987.179.
[20]Eroglu S,Ekren H,Baykara T.Surface hardening of tungsten heavy alloys.Scr Mater.1998;38(1):131.
[21]Ollis DF,Boudart M.Surface and bulk carburization of tungsten single crystals.Surf Sci.1970;23(2):320.
[22]Okoli S,Haubner R,Lux B.Carburization of tungsten and tantalum filaments during low-pressure diamond deposition.Surf Coat Tech.1991;47(1-3):585.
[23]Jung SW,Kim DK,Lee S,Noh JW,Kang SJ.Effect of surface carburization on dynamic deformation and fracture of tungsten heavy alloys.Metall Mater Trans A.1999;30A(8):2027.
[24]Qi XW,Jia ZhN,Yang YL,Fan BL.Characterization and auto-restoration mechanism of nanoscale serpentine powder as lubricating oil additive under high temperature.Tribol Int.2011;44(7-8):805.
[25]Das J,Rao GA,Pabi SK.Microstructure and mechanical properties of tungsten heavy alloys.Mater Sci Eng A.2010;527(s29-30):7841.
[26]Cetinkaya S,Eroglu S.Thermodynamic analysis and effect of temperature on surface hardening of tungsten heavy alloys using ethanol.J Alloys Compd.2015;632:161.
[27]Gao L,Kear BH.Low temperature carburization of high surface area tungsten powders.Nanostruct Mater.1995;5(5):555.
[28]Tsuchida T,Morita N.Formation of ternary carbide Co6W6C by mechanical activation assisted solid-state reaction.J Eur Ceram Soc.2002;22(13):2401.
[29]Chou MCh,Chu Ch F,Wu ShT.Phase transformations of electroplated amorphous iron-tungsten-carbon film.Mater Chem Phys.2002;78(1):59.
[30]Dubrovinskaia NA,Dubrovinsky LS,Saxena SK,Selleby M,Sundman B.Thermal expansion and compressibility of Co6W6C.J Alloys Compd.1999;285(1-2):242.
[31]Suetin DV,Shein IR,Ivanovskii AL.Structural,electronic and magnetic properties of g carbides(Fe3W3C,Fe6W6C,Co3W3Cand Co6W6C)from first principles calculations.Phys B.2009;404(20):3544.
[32]Zafar S,Sharma AK.Development and characterizations of WC-12Co microwave clad.Mater Charact.2014;96(96):241.
[33]Bock A,Zeiler B.Production and characterization of ultrafine WC powders.Int J Refract Met Hard Mater.2002;20(1):23.
[34]Wang GH,Qu ShG,Lai FQ,Li XQ,Fu ZhQ,Yue W.Rolling contact fatigue and wear properties of 0.1C-3Cr-2W-V nitrided steel.Int J Fatigue.2015;77:105.
[35]Cui XH,Wang SQ,Wang F,Chen KM.Research on oxidation wear mechanism of the cast steels.Wear.2008;265(S3-4):468.
[36]Sun Y,Bell T.Sliding wear characteristics of low temperature plasma nitrided 316 austenitic stainless steel.Wear.1998;218(1):34.
[37]Wang L,Xu B,Yu ZhW,Shi QY.The wear and corrosion properties of stainless steel nitrided by low-pressure plasma-arc source ion nitriding at low temperatures.Surf Coat Technol.2000;130(2):304.
[38]Alsaran A.Determination of tribological properties of ion-nitrided AISI 5140 steel.Mater Charact.2002;49(2):171.
[39]Akagaki T,Rigney DA.Sliding friction and wear of metals in vacuum.Wear.1991;149(1-2):353.
[2]Hong SH,Ryu HJ.Combination of mechanical alloying and two-stage sintering of a 93W-5.6Ni-1.4Fe tungsten heavy alloy.Mater Sci Eng A.2003;344(1-2):253.
[3]Hu K,Li XQ,Qu ShG,Li YY.Spark-plasma sintering of W-5.6Ni-1.4Fe heavy alloys:densification and grain growth.Metall Mater Trans A.2013;44(2):923.
[4]Khalid FA.Characterization of in situ carbide coating of tungsten alloy.Mater Sci Eng A.2002;338(1):76.
[5]Luo A,Shin KS,Jacobson DL.High temperature tensile properties of W-Re-ThO2alloys.Mater Sci Eng A.1992;150(1):67.
[6]Hsu C,Lin S.Coalescence of tungsten grains around molybdenum grains in the presence of a liquid phase.Scr Mater.2002;46(12):869.
[7]Kemp PB,German RM.Mechanical properties of molybdenum alloyed liquid phase-sintered tungsten-based composites.Metall Mater Trans A.1995;26(8):2187.
[8]Bose A,German RM.Microstructural refinement of W-Ni-Fe heavy alloys by alloying additions.Metall Mater Trans A.1988;19(12):3100.
[9]Liu M,Cowley J.Particle/dislocation interactions in a dispersion strengthened tungsten alloy at ultrahigh temperatures.Scr Metall Mater.1993;28(3):307.
[10]Park S,Kim D,Lee S,Ryu HJ,Hong SH.Dynamic deformation behavior of an oxide-dispersed tungsten heavy alloy fabricated by mechanical alloying.Metall Mater Trans A.2001;32(8):2011.
[11]Ryu HJ,Hong SH.Fabrication and properties of mechanically alloyed oxide-dispersed tungsten heavy alloys.Mater Sci Eng A.2003;363(1-2):179.
[12]Wu GC,You Q,Wang D.Influence of the addition of lanthanum on a W-Mo-Ni-Fe heavy alloy.Int J Refract Met Hard Mater.1999;17(4):299.
[13]Zhang ZH,Wang FC,Li SK,Wang L.Deformation characteristics of the 93W-4.9Ni-2.1Fe tungsten heavy alloy deformed by hydrostatic extrusion.Mater Sci Eng A.2006;s435-436(6):632.
[14]Hong SH,Ryu HJ.Combination of mechanical alloying and two-stage sintering of a 93W-5.6Ni-1.4Fe tungsten heavy alloy.Mater Sci Eng A.2003;344(1-2):253.
[15]Upadhyaya A,Tiwari SK.Microwave sintering of W-Ni-Fe alloy.Scr Mater.2007;56(1):5.
[16]Song X,Liu X,Zhang J.Neck formation and self-adjusting mechanism of neck growth of conducting powders in spark plasma sintering.J Am Ceram Soc.2006;89(2):494.
[17]Hu K,Li XQ,Qu SG,Li YY.Effect of heating rate on densification and grain growth during spark plasma sintering of 93W-5.6Ni-1.4Fe heavy alloys.Metall Mater Trans A.2013;44(9):4323.
[18]Etsion I,Halperin G,Becker E.The effect of various surface treatments on piston pin scuffing resistance.Wear.2006;261(7-8):785.
[19]Pehlivanturk NY,Inal OT.Carburising of tungsten in a glow discharge methane plasma.In:Spalvins T,editor.Ion Nitriding.ASM International:Ohio;1987.179.
[20]Eroglu S,Ekren H,Baykara T.Surface hardening of tungsten heavy alloys.Scr Mater.1998;38(1):131.
[21]Ollis DF,Boudart M.Surface and bulk carburization of tungsten single crystals.Surf Sci.1970;23(2):320.
[22]Okoli S,Haubner R,Lux B.Carburization of tungsten and tantalum filaments during low-pressure diamond deposition.Surf Coat Tech.1991;47(1-3):585.
[23]Jung SW,Kim DK,Lee S,Noh JW,Kang SJ.Effect of surface carburization on dynamic deformation and fracture of tungsten heavy alloys.Metall Mater Trans A.1999;30A(8):2027.
[24]Qi XW,Jia ZhN,Yang YL,Fan BL.Characterization and auto-restoration mechanism of nanoscale serpentine powder as lubricating oil additive under high temperature.Tribol Int.2011;44(7-8):805.
[25]Das J,Rao GA,Pabi SK.Microstructure and mechanical properties of tungsten heavy alloys.Mater Sci Eng A.2010;527(s29-30):7841.
[26]Cetinkaya S,Eroglu S.Thermodynamic analysis and effect of temperature on surface hardening of tungsten heavy alloys using ethanol.J Alloys Compd.2015;632:161.
[27]Gao L,Kear BH.Low temperature carburization of high surface area tungsten powders.Nanostruct Mater.1995;5(5):555.
[28]Tsuchida T,Morita N.Formation of ternary carbide Co6W6C by mechanical activation assisted solid-state reaction.J Eur Ceram Soc.2002;22(13):2401.
[29]Chou MCh,Chu Ch F,Wu ShT.Phase transformations of electroplated amorphous iron-tungsten-carbon film.Mater Chem Phys.2002;78(1):59.
[30]Dubrovinskaia NA,Dubrovinsky LS,Saxena SK,Selleby M,Sundman B.Thermal expansion and compressibility of Co6W6C.J Alloys Compd.1999;285(1-2):242.
[31]Suetin DV,Shein IR,Ivanovskii AL.Structural,electronic and magnetic properties of g carbides(Fe3W3C,Fe6W6C,Co3W3Cand Co6W6C)from first principles calculations.Phys B.2009;404(20):3544.
[32]Zafar S,Sharma AK.Development and characterizations of WC-12Co microwave clad.Mater Charact.2014;96(96):241.
[33]Bock A,Zeiler B.Production and characterization of ultrafine WC powders.Int J Refract Met Hard Mater.2002;20(1):23.
[34]Wang GH,Qu ShG,Lai FQ,Li XQ,Fu ZhQ,Yue W.Rolling contact fatigue and wear properties of 0.1C-3Cr-2W-V nitrided steel.Int J Fatigue.2015;77:105.
[35]Cui XH,Wang SQ,Wang F,Chen KM.Research on oxidation wear mechanism of the cast steels.Wear.2008;265(S3-4):468.
[36]Sun Y,Bell T.Sliding wear characteristics of low temperature plasma nitrided 316 austenitic stainless steel.Wear.1998;218(1):34.
[37]Wang L,Xu B,Yu ZhW,Shi QY.The wear and corrosion properties of stainless steel nitrided by low-pressure plasma-arc source ion nitriding at low temperatures.Surf Coat Technol.2000;130(2):304.
[38]Alsaran A.Determination of tribological properties of ion-nitrided AISI 5140 steel.Mater Charact.2002;49(2):171.
[39]Akagaki T,Rigney DA.Sliding friction and wear of metals in vacuum.Wear.1991;149(1-2):353.