摘要
研究了在ＳｉＣ晶须表面涂覆１０～１００ｎｍ厚的氧化铝或莫来石对１５％（ｖｏ１）ＳｉＣ＿ｗ／２．５Ｙ－ＴＺＰ陶瓷复合材料力学性能的影响。结果表明：涂层可显著改善复会材料的力学性能，其中涂覆莫来石效果最佳，室温σ＿ｆ＝１４５０ＭＰａ，Ｋ＿（１ｃ）＝１７ＭＰａ·ｍ￣（１／２），１０００℃下σ＿ｆ＝５２０ＭＰａ，比无涂层的复合材料力学性能分别提高了８０％，１００％和４５％，ＳＥＭ，ＴＥＭ和ＨＲＥＭ观察表明：ＳｉＣ＿ｗ表面涂覆Ａｌ＿２Ｏ＿３和莫来石时在ＳｉＣ＿ｗ与ＴＺＰ界面附近形成少量玻璃相，涂层使ＳｉＣ＿ｗ／ＴＺＰ界面的化学结合转变为涂层／ＴＺＰ界面的物理结合，而且涂层降低了界面残余热应力，改善了复合材料的力学性能。
The effect of Al_2O_3 and mullite coatings of 10～100nm thickness on the mechanical properties and interface structure of SiC_w/TZP composites was studied.The experimental results show that the mechanical properties of 15%(vol)SiC_w/2.5Y-TZP are much improved by the Al_2O_3 and mullite coating on the surface of SiC_w. The mechanical properties of reinforced TZP composites with mullite coating on SiC_w surface are σ_f=1450MPa,K_(1c)=17.0MPa·m￣(1/2) at room temperature and σ_f= 500 MPa at 1000℃,These values are 80%,100% and 45%higher than those of reinforced TZP composites without any coating on SiC_w surface,The interfacial phases and lattice images were observed with TEM and HREM. The results show that some amount of glass at the interfaces of SiC_w/Al_2O_3,mullite/TZP is formed so that sintering behaviors of the composites are improved. Because of Al_2O_3 or mullite coating on SiC_w surface,the chemical bonds of interface between SiC_w and TZP are changed into physical bonds between coatings and TZP,and residual thermal stress between SiC_w and TZP de-creases.Therefore the pull out effect of SiC_w with coatings is better than that of SiC_w without any coating.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1994年第1期8-15,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金
关键词
碳化硅晶须
涂层
氧化锆
界面
陶瓷
silicon carbide whisker,coating,tetragonal zirconia polycrystal,composite,interface,mechanical property:
