不同磨粒对ZTA结构陶瓷冲蚀磨损性能的影响

Effect of Different Abrasive Particle Hardness on Erosion Resistant Performance of ZTA Structure Ceramics

针对液/固双相流冲蚀磨损工况,选用不同硬度的SiO2、Al2O3、SiC冲蚀磨粒,对ZTA(ZrO2增韧Al2O)3结构陶瓷和Cr15Mo3高铬铸铁进行了冲蚀磨损性能对比试验,并对试验材料磨损机理和微观失效表面形貌进行了分析和讨论。结果表明:对于同一种硬度的冲蚀磨粒,冲蚀磨损过程中Cr15Mo3高铬铸铁材料的冲蚀磨损多,ZTA陶瓷的冲蚀磨损少;冲蚀磨损过程中浆料固体颗粒硬度越高,试验材料的磨损越多,同时ZTA陶瓷抗冲蚀磨损性能越明显,对应于不同硬度的SiO2、Al2O3、SiC冲蚀磨粒,ZTA陶瓷抗冲蚀磨损性能分别为Cr15Mo3高铬铸铁的5.8、7.0和8.2倍;冲蚀磨损过程中Cr15Mo3材料失效有明显的方向性和腐蚀痕迹,材料的磨损以微切削、梨沟、冲蚀坑为主,"W"型失效形貌明显,材料组织中高硬度的碳化物有保护基体的作用,随着磨粒硬度的增加,材料表面切削、梨沟、冲蚀坑失效程度增加,ZTA陶瓷材料在冲蚀磨损后无明显的冲蚀方向性,材料磨损是晶界粘结相磨失、晶粒裸露为主,细小颗粒ZrO2的存在及增韧作用使陶瓷相中气孔数量少,并减少因疲劳裂纹扩展引起的材料破坏。

The two-phase flow of liquid and solid erosion-corrosion test was carried out to simulate different erosion-corrosion conditions. The effect of different abrasive particle hardness on the erosion-wear resistant performance of Cr15Mo3 high-Cr cast iron and ZTA structure ceramics were studied, and the erosion-wear micro-failure behavior of test materials was analyzed also. The results show that the slurry erosion volume of Cr15Mo3 high-Cr cast iron is bigger than that of ZTA ceramic on erosion-wear, and the erosion-wear resistance of ZTA ceramics is 5.8, 7.0 and 8.2 times higher than that of Cr15Mo3 high-Cr cast iron when the erosive abrasive particle is SiO2, Al2O3 and SiC, respectively. The wear amount of test materials eroded by particle with bigger hardness is also larger than that by particle with smaller hardness. It has been observed by SEM that there exists more corrosive and erosive pit morphology on the worn surface for Cr15Mo3 iron, and some of surface shows clearly ＂W＂ characteristic for Cr15Mo3 iron, compared to smooth worn surface of ZTA ceramics. The reason for better wear resistance of ZTA is because of the finer ZrO2 grain and less pore compared with Cr15Mo3 iron.