摘 要
实现汽车的节能减排，是整个汽车行业所面临的重大挑战。减轻汽车的重量是实现这一宏伟目标的一条有效途径。采用铝制发动机缸体，可以减轻汽车的重量，在其缸体内壁喷涂一层铁基涂层，可以增强铝制缸体的耐磨性。本文采用电弧喷涂技术制备了三种铁基涂层：H08Mn2Si、4Cr13、65Mn。通过金相显微镜和扫描电子显微镜分析了涂层组织特征。这三种涂层材料均具有典型的层状涂层结构特征。三种涂层中以等轴非等轴孔隙居多，缝隙装孔隙最少，且孔隙在空间中呈星形拓扑结构分布。涂层孔隙对于液体的渗透性良好，通过模拟实验证明涂层在润滑条件的磨损状态下，能够一直保持油液的渗入。利用MMU-5G型万能摩擦磨损试验机分别在浸油润滑和干摩擦条件下，测试了涂层材料的摩擦系数，分析了涂层的耐磨性及磨损方式。试验结果表明：在所有磨损试验中，涂层磨损形式主要为磨粒磨损。在干磨条件下，灰铸铁试样的摩擦系数最少，其中的石墨起到的润滑的作用，而铁基涂层中的孔隙无法发挥其减磨作用，导致摩擦系数高于灰铸铁。在50N载荷浸油条件下，4Cr13涂层摩擦系数及耐磨性最好，孔隙起到了储油减磨的作用，三种涂层的摩擦性能均优于灰铸铁。在200N载荷浸油条件下，4Cr13涂层摩擦系数及耐磨性依然优于灰铸铁且在三种涂层中最好，H08Mn2Si涂层的摩擦系数比50N载荷浸油条件下降低幅度最大，说明涂层的摩擦性能要 从本身耐磨性与其各种减磨结构综合衡量。
关键字：热喷涂; 耐磨性; 发动机缸体
Abstract
To realize the energy saving and emission reduction, is a major challenge facing the entire automotive industry. Reduce the weight of the car is an effective way to achieve this goal. Using aluminum engine block, can reduce the weight of the car, in the cylinder wall coating a layer of Fe based coating, can enhance the wear resistance of aluminum cylinder. This paper uses three kinds of Fe based coating by arc spraying technology system: H08Mn2Si, 4Cr13, 65Mn. The analysis of the microstructure of the coating by metallographic microscope and scanning electron microscope. These three kinds of coating materials have the typical characteristics of layered coating structure. Three kinds of coating with equiaxed non equiaxed pores are arranged, slit pores at least, and the por
e space in a star topology. The pores of the coatings for liquid permeability good, wear condition through simulation experiments prove that coating on the lubrication condition, has been able to keep the oil infiltration. Universal friction and wear testing machine were soaked in oil lubrication and dry friction condition by using MMU-5G type, friction coefficient of the coating material were tested, analyzed the wear resistance and wear mode of coatings. The test results show that: in all wear test, the wear mechanisms are mainly abrasive wear. In dry friction condition, and the Fe based coating in the pores and unable to play its role in reducing wear, the friction coefficient is higher than that of gray cast iron. In the loading of 50N oil immersed conditions, friction coefficient and wear resistance of 4Cr13 coating is the best, the pore to reduce abrasion of oil, the friction properties of three kinds of coatings are better than that of grey cast iron. In the loading of 200N oil immersed conditions, the friction coefficient and wear resistance of 4Cr13 coating is better than the gray cast iron and the three kinds of coatings in the best, the friction coefficient of H08Mn2Si coating than 50N under the condition of oil immersed load decrease, the friction properties of the coating itself from the wear resistance and antifriction structure comprehensive measure.
Keywords:锌丝 thermal spraying; wear resistance; engine block
豫公网安备41160202000603
站长QQ:729038198
关于我们
投诉建议