以Cu-25%Sn合金粉、镀铜石墨粉和MoS2粉末为原料,在740~820 ℃烧结温度下制备粉末冶金青铜-石墨-MoS2自润滑材料。利用扫描电镜(SEM)与X射线衍射仪(XRD)观察和分析摩擦材料的显微组织与结构,并测试和分析材料在4 N和10 N载荷下摩擦10 km过程中的摩擦因数和磨损表面形貌。结果表明,随烧结温度升高,青铜-石墨-MoS2自润滑材料的硬度和密度先升高后下降,在780 ℃下烧结的材料,孔隙数量较少、尺寸较小,材料密度和硬度较高;在10 N和4 N载荷下平均摩擦因数分别为0.28和0.36。摩擦过程中材料表面形成一层由石墨和MoS2组成的润滑膜,因而具有自润滑性能,在10 N载荷下的自润滑效果更好。
Powder metallurgy bronze-graphite-MoS2 self-lubricating material was prepared by Cu-25%Sn alloy, copper-coated graphite and MoS2 powders at sintering temperature of 740-820 ℃. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to observe and analyze the microstructure of the sintered materials and wear surface morphology after friction under 4 N and 10 N loads, respectively. The results show that with the increase of sintering temperature, the hardness and density of the bronze-graphite-MoS2 self-lubricating materials show a trend of first increasing and then decreasing. The size and number of pores of the material sintered at 780 ℃ are smaller, so the density and hardness of materials are relatively large. The average friction coefficient under 10 N and 4N loads are 0.28 and 0.36, respectively. In the process of friction and wear, a layer of lubricating film composed of graphite and MoS2 is formed on the surface of the materials, which provides lubrication for the self-lubricating material and a better lubrication effect is under a load of 10 N.
[1] HUTTUNEN S E, ISOTAHDON E, METSAJOKI J, et al.Behaviour of leaded tin bronze in simulated seawater in the absence and presence of tribological contact with alumina counterbody: Corrosion, wear and tribocorrosion[J]. Tribology International, 2019, 129: 257-271.
[2] MA X C, HE G Q, HE D H, et al.Sliding wear behavior of copper graphite material for use in maglev transportation system[J]. Wear, 2008, 265(7): 1087-1092.
[3] MOUSTAFA S F, EL-BADRY S A, SANAD A M, et al. Friction and wear of copper graphite composites made with Cu-coated and uncoated graphite powders[J]. Wear, 2002, 253(7): 699-710.
[4] HUANG S Y, FENG Y, LIU H J, et al.Electrical sliding friction and wear properties of Cu-MoS2-graphite-WS2 nanotubes composites in air and vacuum conditions[J]. Materials Science and Engineering A, 2013, 560(10): 685-692.
[5] GAMON W, ANIOTEK K. Examination of the sliding wear of bronze coatings on railway buffer heads[J]. Wear, 2020, 448/449: 203235.
[6] NOVOSELOV K S, MISHCHENKO A, CARVALHO A, et al.2D materials and van der Waals heterostructures[J]. Science, 2016, 353: 9439.
[7] MENEZES P, NOSONOVSKY M, INGOLE SP, et al.Tribology for Scientists and Engineers: From Basics to Advanced Concepts[M]. New York, USA, Springer, 2013: 478-513.
[8] GAO X M, HU M, FU Y L, et al.MoS2-Au/Au multilayer lubrication film with better resistance to space environment[J]. Journal of Alloy and Compounds, 2020, 815: 152483.
[9] MOAZAMI-GOUDARZI M, NEMATI A.Tribological behavior of self lubricating Cu/MoS2 composites fabricated by powder metallurgy[J]. Transactions of Nonferrous Metals Society of China, 2018, 28(5): 946-956.
[10] XIAO J K, ZHANG W, LIU L M, et al. Tribological behavior of copper-molybdenum disulfide composites[J]. Wear, 2017, 384/ 385(8): 61-71.
[11] KATO H, TAKAMA M, IWAI Y, et al.Wear and mechanical properties of sintered copper-tin composites containing graphite or molybdenum disulfide[J]. Wear, 2003, 255(1/6): 573-578.
[12] ZHANG L, XIAO J K, ZHOU K C.Sliding wear behavior of silver-molybdenum disulfide composite[J]. Tribology Transaction, 2012, 55(4): 473-480.
[13] ZHU J J, MA L, DWYER-JOYCE R S. Friction and wear of Cu-15%Ni-8 %Sn bronze lubricated by grease at room and elevated temperature[J]. Wear, 2020, 460/461: 203474.
[14] ROUHI M, MOAZAMI-GOUDARZI M, ARDESTANI M.Comparison of effect of SiC and MoS2 on wear behavior of Al matrix composites[J]. Transactions of Nonferrous Metals Society of China, 2019, 29(6): 1169-1183.
[15] CHIAPPE D, SCALISE E, CHINQUANTA E, et al.Two-dimensional Si nanosheets with local hexagonal structure on a MoS2 surface[J]. Advanced Materials,2014, 26(13): 2096-2101.
[16] YIN Y G, LIU J W, ZHENG Z X, et al.Effect of graphite on the friction and wear properties of Cu alloy-matrix self-lubricating composites at elevated temperature[J]. Tribology, 2005, 25(3): 216-220.
[17] WANG J, FENG Y, LI S, et al.Influence of graphite content on sliding wear characteristics of CNTs-Ag-G electrical contact materials[J]. Transactions of Nonferrous Metals Society of China, 2009, 19(1): 113-118.
[18] YANG Z R, GUO Z W, YUAN C Q. Effects of MoS2 microencapsulation on the tribological properties of a composite material in a water-lubricated condition[J]. Wear, 2019, 432/433: 102919.
[19] 陈奏君, 林泽华, 段中元, 等. TiH2粉末制备钛合金的组织与力学性能[J]. 粉末冶金材料科学与工程, 2021, 26(3): 243-249.
CHEN Zoujun, LIN Zehua, DUAN Zhongyuan, et al.Microstructure and mechanical properties of titanium alloys prepared with TiH2 powder[J]. Materials Science and Engineering of Powder Metallurgy, 2021, 26(3): 243-249.
[20] KHARE H S, BURRIS D L.The Effects of environmental sater and oxygen on the temperature-dependent friction of sputtered molybdenum disulfide[J]. Tribology Letters, 2013, 52(3): 485-493.
[21] HAO R, TEDSTONE A A, LEWIS D J, et al.Property self-optimization during wear of MoS2[J]. ACS Applied Materials and Interfaces, 2017, 9(2): 1953-1958.
[22] LEE C G, LI Q Y, KALB W, et al.Frictional characteristics of atomically thin sheets[J]. Science, 2010, 328(5974): 76-80.
