几种陶瓷和金属等离子喷涂层/铸铁副的摩擦学特性研究

Investigation on Tribological Behavior of Several Plasma Sprayed Ceramic Coatings Against Cast Iron

本文对等离子喷涂ZrO_2+MgO和Al_2O_3+40％ZrO_2陶瓷涂层、Mo+NiCrBSi(Ar/H_2)和Mo+NiCrBSi(N_2/H_2)混合粉末涂层,以及Mo+4％O_2渗氧涂层等的摩擦学特性进行了试验研究,测定了它们的抗咬合裁荷及其在边界润滑状态下的磨损率。结果表明,Al_2O_3+40％ZrO_2陶瓷涂层/铸铁副的抗咬合性能最好,在其轻度粘着的表面上形成了一层表面膜;Mo+NiCrBSi(N_2/H_2)金属涂层是一种实用性能较好的活塞环材料;在粘着磨损条件下,涂层材料的抗咬合性越好,与之配磨的铸铁材科的磨损率越低;涂层材料的抗咬合性与其本身的固有特性及孔隙率等有关。

Plasma sprayed ceramic coatings and metallic composite coatings have a wide application in the ring-cylinder components of various engines. In this paper, Al2O3-40%ZrO2, ZrO2-MgO ceramic coatings and Mo + NiCrBSi (Ar/H2), Mo + NiCrBSi (N2/H2) and Mo doped oxygen composite metallic coatings were investigated. The seizure resistance characteristics of these five ceramic and metallic composite coatings against cast iron have been evaluated under lubrication with CD grade mineral oil at 300℃, and the wear rates under the boundary lubrication (250℃, 300N,60min) have been tested. All friction and wear experiments were carried out on a SRV test machine. The parameters, such as temperature, load, frequency, stroke and time, can be set up according to the experiment requisition. The wear surfaces were observed with CSM950 scanning electric microscope and TN5402 energy dispersion microanalysis of X-ray. The wear rate was calculated according to the depth of wear tracks measured with a Talysurf-5 profile meter communicated with VAX8350 computer system. The results indicated that the seizure resistance of Al2O3-40%ZrO2/ cast iron couple is better than that of ZrO2-MgO,and the Mo+NiCrBSi (Ar/N2)cast iron couple is the best among the three metallic composite coatings in seizure resistance. It seems that Al2O3-40%ZrO2/cast iron is promising in practical application and worthwhile furthur research. Under adhesive wear mode, the better the couple's seizure resistance, the lower the wear rate of the matched cast iron specimen bath for ceramic coatings and metallic coatings. The seizure resistance properties are closely related to the inherent properties of coating material itself, the compatibility between lubricant and coating material and the coating porosity. The increasing of coating material porosity is beneficial to improving lubrication and seizure resistance, but high porosity results in a severe wear.