镍基自润滑涂层的制备及拉伸结合强度研究

发布时间：2019-08-17 12:48

【摘要】：采用等离子喷涂与粉末冶金方法分别制备了PS304、PM304镍基自润滑涂层,并对涂层的组织、拉伸结合强度进行了研究。结果表明:采用等离子喷涂制备的PS304涂层组织粗大、孔隙率高、润滑相与强化相分布不均匀。而采用高能球磨与真空烧结技术制备的PM304涂层组织均匀、致密、粒子明显细化。拉伸试验表明:PS304的拉伸结合强度较低,拉伸断口不仅出现在涂层与基底的结合处、也出现在涂层内部;而PM304的拉伸结合强度较高,涂层与基底之间结合良好、结合方式为冶金结合,拉伸断口主要出现在涂层内部。PM304涂层拉伸强度增大的原因主要为:(1)致密度提高;(2)尖锐孔隙数量降低;(3)Ag与Ni Cr之间形成冶金结合;(4)Ni Cr基体中析出粒子的弥散强化作用使得Ni Cr基体强度提高。
[Abstract]:PS304,PM304 nickel-based self-lubricating coatings were prepared by plasma spraying and powder metallurgy, respectively. the microstructure and tensile bonding strength of the coatings were studied. The results show that the microstructure of PS304 coating prepared by plasma spraying is coarse, the porosity is high, and the distribution of lubricating phase and strengthening phase is uneven. The microstructure of PM304 coating prepared by high energy ball milling and vacuum sintering is uniform, dense and the particles are obviously refined. The tensile test shows that the tensile bonding strength of PS304 is low, and the tensile fracture appears not only in the bonding between the coating and the substrate, but also in the coating, while the tensile bonding strength of PM304 is higher, the bonding between the coating and the substrate is good, the bonding mode is metallurgical bonding, and the tensile fracture mainly appears in the coating interior. The main reasons for the increase of the tensile strength of PM304 coating are as follows: (1) the density increases, (2) the number of sharp pores decreases, and the tensile fracture surface of PM304 coating increases as follows: (1) the density increases, (2) the number of sharp pores decreases; (3) Metallurgical bonding between Ag and Ni Cr is formed, and (4) the dispersion strengthening of precipitated particles in) Ni Cr matrix increases the strength of Ni Cr matrix.
【作者单位】：西安交通大学机械结构强度与振动国家重点实验室;
【基金】：国家自然科学基金(51171143,51275386) 中央高校基础研究基金以及新世纪优秀人才计划(NCET-11-0418) 国家重点基础研究发展计划(“973”计划)(2013CB035705)
【分类号】：TG178

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