Study On The Preparing And Erosion Properties Of ZrO₂-SiC Composite Materials

Zirconia ceramic has attracted wide attention by scholars from different countries due to its high strength,high-toughness,high hardness and good chemical stability and so on.TZP ceramic is one of the most widely used engineering materials with its excellent mechanical properties,but when it is used at high temperature,the properties of TZP degrade drastically.Therefore,one alternative for improvement of mechanical properties of TZP is the addition of SiC as a second reinforced phase with high strength,high hardness,good chemical and thermal stability.In this paper,90 #, 320 #,600 #,1500 # of SiC,3Y-ZrO₂ powder,8Y-ZrO₂ powder,Al₂O₃ powder as raw materials 3YSZ-SiC,3YSZ-Al₂O₃-SiC,8YSZ-SiC,8YSZ-Al₂O₃-SiC composites were prepared.The relationship between phase composition,microstructure and mechanical properties,erosion wear properties of these composites was investigated.And the effect of SiC particles size,amount of SiC particles in composites and the additive amount of zirconium oxide on properties of silicon carbide composite material was studied.The results showed that:8YSZ-SiC composite ceramics prepared in 1550℃×3h under the protection of nitrogen atmosphere,when added to 3wt.%Of the 1500# SiC, the bulk density,bending strength and Rockwell hardness of samples got their highest value,respectively,5.31g·cm^-3,81MPa and 84.9HRA.For 8YSZ-Al₂O₃-SiC composite ceramics sintered at 1550℃×3h in nitrogen atmosphere,when the addition of 1500# SiC particle was 3wt.%,The maximum bulk density of the sample can get 5.27g·cm^-3;while the addition of 1500# SiC is 6wt.%,apparent porosity and maximum flexural strength of samples,were 0.07%and 246MPa.Study showed that for 3YSZ-SiC composite materials,the erosion rate with the addition of 320# SiC increased gradually increase.For the 8YSZ-SiC materials,when the addition of the 1500# SiC particles was 6wt.%.The lowest volume erosion rate of samples was 0.07×10^-6cm³/mm²hr.For the 8YSZ-Al₂O₃-SiC composite materials, when the addition of the 1500# SiC particles was 3wt.%.,the minimum volume erosion rate of the samples was 0.32×10^-6cm³/mm²hr.High-temperature solid particle erosion experiments showed that tetragonal zirconia was easily cracked in high temperature conditions due to its phase transformation,adding 5wt.%SiC can improve its high temperature erosion wear performance.Rigid particles added into composites as a second phase can improve the corrosion wear performance of materials.