摘要
为了提高TC4钛合金表面摩擦磨损和高温抗氧化性能,以NiCrCoAlY+20%(质量分数)Cr_(3)C_(2)混合粉末作为熔覆粉末,采用激光熔覆技术在TC4钛合金表面制备NiCrCoAlY-Cr_(3)C_(2)复合涂层,利用OM,SEM,XRD,EDS等分析涂层的显微组织和物相组成;采用HXD-1000TB显微硬度计测量涂层显微硬度;采用MMG-500三体磨损试验机与WS-G150智能马弗炉对涂层和基体进行摩擦磨损及高温抗氧化实验。结果表明:利用激光熔覆技术在TC4钛合金表面可以制备形貌良好、无裂纹和气孔等缺陷的复合涂层。熔覆区显微组织结构致密,多为针状晶和树枝晶;结合区的显微组织主要由平面晶、胞状晶和树枝晶组成,生成了多种可提高耐磨性和高温抗氧化性的碳化物、氧化物和金属间化合物。复合涂层的最高显微硬度为1344HV,约为钛合金基体350HV的3.8倍;复合涂层的摩擦因数为0.2~0.3,较钛合金基体的摩擦因数0.6~0.7明显下降;相同条件下复合涂层的磨损失重为0.00060 g,是钛合金基体磨损失重0.06508 g的0.9%;恒温850℃氧化100 h后复合涂层氧化增重为6.01 mg·cm^(-2),约为钛合金基体氧化增重25.10 mg·cm^(-2)的24%。激光熔覆技术有效改善了TC4钛合金表面的摩擦磨损和高温抗氧化性能。
In order to improve the surface friction,wear and high temperature oxidation resistance of TC4 titanium alloy,NiCrCoAlY+20%(mass fraction)Cr_(3)C_(2) mixed powder was selected as the cladding powder to prepare NiCrCoAlY-Cr_(3)C_(2) composite coating on the surface of TC4 titanium alloy by using laser cladding technology.The microstructure and phase composition of the coating were analyzed by OM,SEM,XRD,EDS,etc.The microhardness of the coating was measured by HXD-1000TB tester.MMG-500 three-body wear tester and WS-G150 smart muffle furnace were used to test the friction,wear and high temperature oxidation resistance of the coating and substrate.The results show that the laser cladding technology can be used to prepare the good composite coating on the surface of TC4 titanium alloy without cracks and pores.The microstructure of the cladding zone is dense,mostly needle-like crystals and dendrites.The microstructure of the bonding zone is mainly composed of planar crystals,cellular crystals and dendrites,which generates a variety of products including the carbides,oxides and intermetallic compounds that can improve wear resistance and high temperature oxidation resistance.The maximum microhardness of the composite coating is 1344HV,which is about 3.8 times of the 350HV of the titanium alloy substrate.The friction factor of the composite coating is 0.2-0.3,which is significantly lower than the friction factor of the titanium alloy substrate of 0.6-0.7.Under the same conditions,the wear mass loss of the composite coating is 0.00060 g,which is 0.9%of that of 0.06508 g of titanium alloy substrate.After oxidation at 850℃for 100 h,the oxidation mass gain of the composite coating is 6.01 mg·cm^(-2),which is about 24%of that of 25.10 mg·cm^(-2) of titanium alloy substrate.Laser cladding technology effectively improves the friction and wear performance and high temperature oxidation resistance of the TC4 titanium alloy surface.
作者
覃鑫
祁文军
左小刚
QIN Xin;QI Wen-jun;ZUO Xiao-gang(School of Mechanical Engineering,Xinjiang University,Urumqi 830017,China;Xinjiang Joinworld Company Limited,Urumqi 830013,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2021年第12期107-114,共8页
Journal of Materials Engineering
基金
新疆维吾尔自治区高校科研计划自然科学重点项目(XJEDU2020I007)
国家大学生创新训练计划项目(201910755067)
新疆维吾尔自治区自然科学基金(2021D01C051)。
关键词
TC4钛合金
激光熔覆
显微组织
磨损性能
高温抗氧化性能
TC4 titanium alloy
laser cladding
microstructure
wear property
high temperature oxid-ation resistance
