Page 126 - 《摩擦学学报》2021年第3期

第 3 期 祝杨, 等: Ti6Al4V合金激光熔覆Ti 3 SiC 2 增强Ni60复合涂层组织与摩擦学性能 415

Therefore, two kinds of Ti 3 SiC 2 /Ni60 composite coatings, i.e. 5% Ti 3 SiC 2 + Ni60 (N1) and 10%Ti 3 SiC 2 + Ni60
(N2)(weight fraction) were prepared by laser cladding technology on the Ti6Al4V alloy to enhance the wear resistance
and friction reduction performance. The microstructure, microhardness, tribological performance and the related wear
mechanisms of the composite coatings were investigated at room temperature (RT), 300 and 600 ℃ by using various
characterization methods (scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer). According
to the results, the composite coatings were mainly composed of hard phase TiC/TiB/Ti x Ni y , γ-Ni solid solution
continuous phase and lubricating phase Ti 3 SiC 2 at room temperature; however, at high temperature, dense oxide films of
TiO 2 and SiO 2 with certain lubricating effect were produced. In addition, the microhardnesses of N1 and N2 composite
coatings were 1 101.90HV 0.5 and 1 037.23HV 0.5 , respectively, which were about three times that of the substrate
(350HV 0.5 ), due to the effects of dispersion strengthening, solid solution strengthening, fine grain strengthening and the
feature of ternary lubricating phase Ti 3 SiC 2 with the dual effects of metal and ceramic. The coefficients of friction (COF)
of the N1 composite coatings at room temperature, 300 and 600 ℃ were 0.39, 0.35 and 0.30, while the N2 composite
coatings were 0.41, 0.45 and 0.44, which both were lower than those of substrate (0.51, 0.49, 0.47). The wear rates of N1
−5 −5 −5 3
and N2 composite coatings at room temperature, 300 and 600 ℃ were 3.07×10 , 1.47×10 , 0.77×10 mm /(N·m) and
−5 −5 −5 3
1.45×10 , 0.96×10 , 0.62×10 mm /(N·m) respectively, which both were far lower than those of the substrate
−5 −5 −5 3
[35.96×10 , 25.99×10 , 15.18×10 mm /(N·m)]. It can be seen that the addition of ternary solid lubricating phase
Ti 3 SiC 2 improved the wear resistance and friction reduction properties of Ti6Al4V alloy in this work, rendering N1
composite coating better friction reducing performance and N2 composite coating better wear resistance. At room
temperature, the wear of the substrate was mainly caused by abrasive wear, adhesive wear and plastic deformation; while
abrasive wear, mild adhesive wear and plastic deformation were the main wear mechanisms of the two composite
coatings. In the high temperature wear process, the surface of Ti6Al4V alloy was dominated by oxidation wear, adhesive
wear, abrasive wear and mild plastic deformation. At 300 ℃, three-body abrasive wear, adhesive wear and oxidation
wear were the main wear mechanisms of the two composite coatings. At 600 ℃, the main wear mechanisms were
abrasive wear, adhesive wear and oxidation wear, and the plastic deformation of N2 composite coating was relatively
severe.
Key words: Ti6Al4V alloy; Ti 3 SiC 2 ; laser cladding; wear-resistance and anti-friction properties; composite coatings

Ti6Al4V合金的综合力学性能优异，因而被广泛 现优异.
地应用于喷气发动机的压气盘、耐压艇体、水上船舶 Ni60合金粉末具有耐磨性好和硬度高等特点，常
的泵体及工业机身的防火壁等. 但由于其在高温环境 被用作激光熔覆材料 [8-9] . 而Ti SiC 作为一种典型的三
2
3
中的抗氧化性及摩擦学性能均有明显缺陷，限制了其 元层状M n+1 AX 相材料，同时结合了金属优越的可加
n
工性、物理特性和陶瓷优良的热稳定性、抗氧化性、自
在高温条件下的应用，因此在Ti6Al4V合金表面研究
[10]
润滑特性等 ，但其摩擦性能在室温下并没有表现出
出高温条件下具有优异摩擦学性能的复合涂层具有
明显的优势 ，然而在作为复合涂层的掺杂物时，其
[11]
重要意义 [1-4] .
[12]
层状结构的特点表现出优异的自润滑性能 . Yan等 [10]
激光熔覆技术在涂层制备及损伤修复等领域中
利用激光技术原位合成了Ni25/Ti SiC 复合涂层，结
2
3
[6]
[5]
应用广泛 . Shakti等 采用激光包覆技术在合金表面
果表明，室温下复合涂层的显微硬度(850.6HV )明显
0.2
制备出了优异的AlN/Ni/Ti6Al4V涂层，结果表明：涂
高于基体360(HV )，另外，由于润滑相Ti SiC 与陶瓷
0.2
2
3
层的表面没有出现宏观裂纹和气孔，其组分主要为Ni Ti、
3 相TiC/Ti Si 的协同作用，涂层的摩擦系数(0.33)相比
5
3
Ti AlN等金属间化合物，涂层的显微硬度提高到1 000~ 于基体(0.43)有明显地下降，磨损率也仅为基体磨损
3
1 250HV ，约为基体(370HV )的3倍，涂层的摩擦系 率25.7×10 mm /(N·m)的一半左右，显著提高了Ti6Al4V
3
−5
0.5
0.5
数(0.4)相比于基体(0.5)也有所降低. Obadele等 选择 合金的强度和摩擦学性能.
[7]
TiNi/TiNiZrO 体系作为耐磨涂层用于加强Ti6Al4V合 为了丰富激光熔覆材料体系，深入探究Ti SiC 在
2 3 2
金表面抗腐蚀磨损性能，该涂层由TiNi/Ti Ni相组成， 涂层中的效应，本次工作中设计了两种纯Ti SiC 与
2
2
3
且激光熔覆的快速冷凝以及ZrO 的加入使涂层的微 Ni60粉末的混合比例，并采用同步送粉法制备Ti SiC /
2
3
2
观组织从枝晶结构变为更加均匀致密的花状结构，从 Ni60/Ti6Al4V复合涂层，系统地研究了其在宽温域下
而使复合涂层在室温下的硬度和耐腐蚀磨损性能表 的微观形貌、显微硬度、物相组成、摩擦学性能及相关