多组元钛铝基自润滑复合材料及其摩擦学研究
发布时间：2018-08-25 17:58
【摘要】：液体润滑剂在高温下容易失效,润滑涂层寿命有限,而固体自润滑复合材料不仅在极端工况下具有优秀的摩擦学性能,而且由于自我修复能力拥有较长的使用寿命,成为摩擦学的一个热门研究领域。由于单一的润滑剂很难在较宽的温度范围内实现润滑效果,因此对两种或两种以上润滑剂协同润滑的研究十分必要。本论文首次以TiAl合金为基体,通过添加复合润滑组元Ag、Ti3SiC2和BaF2/CaF2共晶体(ATBC)制备出新型的TiAl基自润滑材料。含复合润滑组元ATBC的Ti Al基自润滑材料在室温(RT)-600°C的摩擦磨损性能被研究。研究结果表明由于Ag、Ti3SiC2和BaF2/CaF2共晶体的协同润滑作用,该TiAl基自润滑材料在所有测试温度范围内都具有优秀的摩擦学性能。以前的研究中,通常通过在基体中添加固体润滑剂来制备自润滑复合材料。当润滑剂含量较低时,复合材料摩擦学性能的改善不明显,当润滑剂含量较高时,复合材料的力学性能会明显降低。在基体中添加有效的增强相,将会是提高复合材料的强度和耐磨性能的一种有效方法。本论文选择TiB2来提高TiAl-12Ag自润滑复合材料的强度。研究了含润滑剂Ag和增强相TiB2的TiAl基自润滑材料在RT到600°C的摩擦磨损性能。结果显示复合材料的耐磨性得到了明显的提高。TiAl-12Ag-5TiB2复合材料在不同工况条件(载荷、滑动速度和不同摩擦副材料)下的摩擦学性能被研究。复合材料的摩擦学性能依赖于工况条件,在一定载荷范围内,摩擦系数随着载荷的增加而降低,磨损率随着载荷的增加而增大;在一定滑动速度范围内,摩擦系数和磨损率随着滑动速度的升高而降低;相对于Al2O3和WC-6Co,以Si3N4为摩擦副时,TiAl-12Ag-5TiB2自润滑复合材料表现出了最优良的摩擦磨损性能。自润滑复合材料优秀的摩擦学性能归因于磨痕表面理想的摩擦层的形成。本文研究了TiAl-12Ag-5TiB2复合材料摩擦层形成和作用机理。当载荷为12N时,由润滑膜、机械混合层和塑性变形层组成的摩擦层形成。塑性变形层加强了材料抵抗变形的能力,与其它层之间的结合强度高;机械混合层主要由润滑相组成,为磨痕表面润滑膜的铺展提供物质支持,而连续完整的润滑膜具有低剪切强度,能够发挥良好的润滑效果,从而有效地降低材料的摩擦系数和磨损率。
[Abstract]:Liquid lubricant is easy to fail at high temperature, and the life of lubricating coating is limited. Solid self-lubricating composite not only has excellent tribological properties under extreme conditions, but also has long service life due to self-repairing ability. It has become a hot research field in tribology. Because a single lubricant is difficult to achieve lubricating effect in a wide range of temperatures, it is necessary to study the synergistic lubrication of two or more lubricants. In this paper, a new self-lubricating material based on TiAl was prepared by adding Ag,Ti3SiC2 and BaF2/CaF2 eutectic (ATBC) as the base of TiAl alloy for the first time. The friction and wear properties of Ti Al based self-lubricating materials containing composite lubricating component ATBC at room temperature (RT) -600 掳C were investigated. The results show that the self-lubricating material based on Ag,Ti3SiC2 and BaF2/CaF2 has excellent tribological properties in all test temperatures due to the synergistic lubrication effect between TiAl and BaF2/CaF2 eutectic. In previous studies, self-lubricating composites were usually prepared by adding solid lubricants to the matrix. When the lubricant content is low, the tribological properties of the composites are not improved obviously, but the mechanical properties of the composites decrease obviously when the lubricant content is higher. Adding effective reinforcing phase to the matrix will be an effective method to improve the strength and wear resistance of the composites. In this paper, TiB2 is chosen to improve the strength of TiAl-12Ag self-lubricating composites. The friction and wear properties of TiAl based self-lubricating materials containing lubricant Ag and reinforced phase TiB2 at RT to 600 掳C were studied. The results show that the wear resistance of the composites has been obviously improved. The tribological properties of the composites under different working conditions (load, sliding speed and different friction pairs) have been studied. The tribological properties of the composites depend on the working conditions. In a certain range of loads, the friction coefficient decreases with the increase of the load, and the wear rate increases with the increase of the load. The friction coefficient and wear rate decrease with the increase of sliding speed, and the friction and wear properties of TiAl-12Ag-5TiB2 self-lubricating composite show the best performance compared with that of Al2O3 and WC-6Co, when Si3N4 is used as friction pair. The excellent tribological properties of self-lubricating composites are attributed to the formation of an ideal friction layer on the wear-mark surface. In this paper, the formation and mechanism of friction layer of TiAl-12Ag-5TiB2 composites are studied. When load is 12 N, friction layer is formed by lubricating film, mechanical mixing layer and plastic deformation layer. The plastic deformation layer strengthens the ability of material to resist deformation and has high bonding strength with other layers. The mechanical mixing layer is mainly composed of lubricating phase, which provides material support for the spreading of lubricating film on the wear mark surface. The continuous and complete lubrication film has low shear strength and can play a good lubricating effect, thus effectively reducing the friction coefficient and wear rate of the material.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB333
本文编号：2203664
[Abstract]:Liquid lubricant is easy to fail at high temperature, and the life of lubricating coating is limited. Solid self-lubricating composite not only has excellent tribological properties under extreme conditions, but also has long service life due to self-repairing ability. It has become a hot research field in tribology. Because a single lubricant is difficult to achieve lubricating effect in a wide range of temperatures, it is necessary to study the synergistic lubrication of two or more lubricants. In this paper, a new self-lubricating material based on TiAl was prepared by adding Ag,Ti3SiC2 and BaF2/CaF2 eutectic (ATBC) as the base of TiAl alloy for the first time. The friction and wear properties of Ti Al based self-lubricating materials containing composite lubricating component ATBC at room temperature (RT) -600 掳C were investigated. The results show that the self-lubricating material based on Ag,Ti3SiC2 and BaF2/CaF2 has excellent tribological properties in all test temperatures due to the synergistic lubrication effect between TiAl and BaF2/CaF2 eutectic. In previous studies, self-lubricating composites were usually prepared by adding solid lubricants to the matrix. When the lubricant content is low, the tribological properties of the composites are not improved obviously, but the mechanical properties of the composites decrease obviously when the lubricant content is higher. Adding effective reinforcing phase to the matrix will be an effective method to improve the strength and wear resistance of the composites. In this paper, TiB2 is chosen to improve the strength of TiAl-12Ag self-lubricating composites. The friction and wear properties of TiAl based self-lubricating materials containing lubricant Ag and reinforced phase TiB2 at RT to 600 掳C were studied. The results show that the wear resistance of the composites has been obviously improved. The tribological properties of the composites under different working conditions (load, sliding speed and different friction pairs) have been studied. The tribological properties of the composites depend on the working conditions. In a certain range of loads, the friction coefficient decreases with the increase of the load, and the wear rate increases with the increase of the load. The friction coefficient and wear rate decrease with the increase of sliding speed, and the friction and wear properties of TiAl-12Ag-5TiB2 self-lubricating composite show the best performance compared with that of Al2O3 and WC-6Co, when Si3N4 is used as friction pair. The excellent tribological properties of self-lubricating composites are attributed to the formation of an ideal friction layer on the wear-mark surface. In this paper, the formation and mechanism of friction layer of TiAl-12Ag-5TiB2 composites are studied. When load is 12 N, friction layer is formed by lubricating film, mechanical mixing layer and plastic deformation layer. The plastic deformation layer strengthens the ability of material to resist deformation and has high bonding strength with other layers. The mechanical mixing layer is mainly composed of lubricating phase, which provides material support for the spreading of lubricating film on the wear mark surface. The continuous and complete lubrication film has low shear strength and can play a good lubricating effect, thus effectively reducing the friction coefficient and wear rate of the material.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB333
【参考文献】
相关期刊论文 前10条
1 王孟光;孙建科;陈志强;;TiAl基合金的熔炼与铸造成形工艺研究现状[J];钛工业进展;2010年04期
2 李文虎;;TiAl基陶瓷复合材料的研究现状[J];陶瓷学报;2009年03期
3 杨丽颖;王砚军;刘佐民;;Ti-Al合金高温自润滑材料抗摩擦磨损模型[J];中国机械工程;2008年05期
4 李玉峰;欧阳家虎;周玉;;高温固体润滑材料研究的发展现状[J];热处理技术与装备;2007年06期
5 岳云龙,吴海涛,吴波,王志杰,陶文宏;TiAl化合物的热爆合成热力学与动力学分析[J];济南大学学报(自然科学版);2005年02期
6 岳云龙,吴海涛,王志杰,张联盟;TiAl金属间化合物的研究进展[J];济南大学学报(自然科学版);2004年01期
7 王黎钦,应丽霞,古乐,张三川;固体自润滑复合材料研究进展及其制备技术发展趋势[J];机械工程师;2002年09期
8 彭超群,黄伯云,贺跃辉;TiAl合金设计与成形方法[J];粉末冶金技术;2001年05期
9 刘如铁,李溪滨,程时和;金属基固体自润滑材料的研究概况[J];粉末冶金工业;2001年03期
10 彭超群,黄伯云,贺跃辉;合金化对TiAl基合金性能的影响及机理[J];中国有色金属学报;1998年S1期
相关博士学位论文 前1条
1 杨丽颖;高温自润滑TiAl基合金的制备及其性能研究[D];武汉理工大学;2008年
相关硕士学位论文 前1条
1 徐增师;钛铝基自润滑复合材料的摩擦学特性研究[D];武汉理工大学;2013年
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