Erosion Wear Resistance Of Zirconia Ceramics At Elevated Temperature

Solid particle erosion is a phenomenon or a process that solid particles entrain ina fluid stream striking the surface of the target material with a specific velocity andangle, and finally make the target material removal. Solid particle erosion at elevatedtemperature is the main cause of destroying the materials and apparatuses in industries.ZrO₂ceramics show good erosion wear resistance at room temperature as its highfracture toughness, high hardness and excellent corrosion resistance as wearcomponents. But its continuous high temperature service life and circulating servicelife turn to dramatically short owning to the decreasing of fracture toughness of theceramic caused by the failure of phase transformation toughening at high temperature.Some questions like low experiment and unsystematic research are still existed in thestudy on erosion wear resistance of ZrO₂ceramics. Hence, systematic study andevaluation of solid particle erosion wear resistance of ZrO₂ceramics from roomtemperature to1400℃are very important and urgent.Dense3YSZ,5YSZ,8YSZ, MgSZ, CeSZ were prepared in this study. Thedependence of experiment temperature and erosion angle on the volume erosion rateof ZrO₂ceramics was focused. The effect of bending strength, fracture toughness andelastic modulus on the solid particle erosion wear resistance of ZrO₂ceramics atelevated temperature was researched. The erosion mechanisms at differenttemperature were dicussed.The results shows: Bending strength, fracture toughness and elastic modulus of3YSZ ceramics were highest and reached714MPa,16.2MPa·m1/2and142.6Gpa,respectively. The mechanical properties of3YSZ,5YSZ, MgSZ declined dramaticallyas the temperature increasing, but kept steady at1000℃¹400℃. Bending strength,fracture toughness and elastic modulus of3YSZ,5YSZ, MgSZ ceramics were at therange of120¹70MPa,2.8³.9MPa·m1/2and42⁵7Gpa, respectively at1400℃.The volume erosion rate of3YSZ,5YSZ,8YSZ, MgSZ and CeSZ ceramicsincreased gradually as the temperature going up. The erosion rate presented a lineargrowth with a low slope when the temperature was between room temperature and 600℃. The growth rate of erosion rate increased significantly as the temperature rosefrom800℃to1000℃. While the erosion rate tended to be stable when thetemperature was higher than1000℃. The volume erosion rate of3YSZ,5YSZ,8YSZ,MgSZ and CeSZ ceramics increased gradually as the erosion angle rose. The erosionrate of3YSZ ceramics was the smallest when eroded at30oangle.When the experimental temperature was less than800℃, the major erosionmechanism of3YSZ,5YSZ, MgSZ ceramics is plastic deformation. When subjectedto particles impact at elevated temperature （800℃¹400℃）, the material removalcan be seen to be by lateral crack intersections for an ideally brittle material. Whenthe ceramics were eroded at a small angle （<60°）, plastic deformation minor chippingbecame the major erosion mechanisms. Minor chipping could also be seen in the caseof ZrO₂ceramic eroded at90°angle and room temperature. The change of erosionmechanism from plastic deformation to lateral crack intersections was obvious as theerosion angle increasing. Materials removal of3YSZ ceramic was identical with thatof typical brittle materials when the experimental temperature was between600℃¹200℃, however, it turned to be a brittle-plastic transition process when3YSZ ceramics were eroded at1400℃or less than400℃.