石英添加量对搪瓷涂层微观结构及摩擦磨损性能的影响

采用一次浸搪法制备石英添加量为0%、4%、8%和12%的搪瓷涂层，通过HSR-2M型高速往复摩擦试验机测试涂层摩擦学性能，SEM和EDS分别表征涂层微观组织和磨损形貌，并分析磨损机理. 结果表明:搪瓷涂层中石英添加质量分数为0%和4%时，涂层气孔率大、气孔密度低，摩擦时形成的微裂纹易沿着气孔间最短距离方向扩展，硬质磨屑转移至摩擦对偶表面而使涂层磨痕底部形成尖锐的凹槽，磨损形式主要为磨粒磨损和脆性断裂. 而石英添加质量分数为8%和12%的涂层气孔率小、气孔密度高，其中8%添加量涂层的孔径分布更加均匀，磨损率及磨痕深度仅为未添加涂层的1/3. 摩擦过程中孔径均匀的小尺寸气孔增大了裂纹扩展时所需的能量势垒而阻碍裂纹扩展，磨屑被气孔拦截后在磨损表面形成密实的堆积层，避免了摩擦对偶与涂层的直接接触而起到减摩作用，磨损形式主要为磨粒磨损. 

Quartz Addition Effects on Microstructure and Friction Wear Properties of Enamel Coating

Enamel coatings with the quartz addition amount of 0%, 4%, 8% and 12% were prepared by the single dipping method. The tribological properties of the coating were tested by HSR-2M high-speed reciprocating friction tester. In order to analyze the wear mechanism, scanning electron microscope was used to characterize the microstructure and the wear morphology of enamel coatings. Results showed that when the addition amounts of quartz were 0% and 4%, the enamel coatings had high porosity and low pore density. Microcracks tended to extend along the shortest distance among the pores, and the hard abrasives transferred to the worn surface during the friction process, which made sharp grooves at the bottom of the sliding wear track. The main wear mechanisms were abrasive wear and brittle fracture. While the addition amounts of quartz were up to 8% and 12%, the enamel coatings had low porosity and high pore density. And the size distribution of pores for 8% quartz coating was uniform, and the wear rate and wear track depth were only one third of that of 0% quartz coating. Small pores with uniform diameter increased the energy barrier for crack propagation during the friction process, and a dense self-lubrication accumulation layer of wear debris formed on the worn surface because of the interception of the small uniform pores in enamel coating. The wear mechanism was mainly abrasive wear.