摘要
凝胶注模成型工艺的关键在于制备低粘度高固相体积含量的陶瓷浆料。本文以四甲基氢氧化铵(TMAH)溶液为分散剂制备氮化硅陶瓷浆料,研究了pH值、分散剂含量、助烧剂含量以及固相体积含量对氮化硅浆料流变性的影响;测定了凝胶注模成型素坯以及烧结体的力学性能。研究结果表明:当pH=10.5,分散剂加入量为6%(相对于氮化硅固相体积比),助烧剂加入量为10%(质量分数)时,浆料具有最好的流变性。根据以上制备的工艺参数,制备得到固相体积含量大于50%,具有良好流变性的浆料。铸模成型干燥后,素坯的抗弯强度达27 MPa;常压烧结后氮化硅陶瓷具有优异的力学性能,其抗弯强度为730 MPa,断裂韧性高达8.8 MPa.m1/2。
Preparation of ceramic slurry with low viscosity and high solid loading is the key process in gel-casting process.The Si3N4 slurry was prepared using TMAH as dispersant in this paper.The influences of pH value,content of dispersant and sintering additives and solid loading on rheological properties of Si3N4 slurry were studied.Mechanical properties of green body and sintered body prepared by gel-casting were investigated.The results showed that the rheological properties of Si3N4 slurry has the best when pH value is 10.5,and the amount of dispersant solution（respect to Si3N4 solid volume） is 6% and sintering additives（wt%） is 10% respectively.According to the optimized processing parameters,the high solid loading（50%） of Si3N4 slurry with good fluidity have been prepared（viscocity100 mPa·s.Flexural strength of green body is 27 MPa after forming.The Si3N4 samples after sintering have excellent mechanical properties with flexural strength of 730 MPa and fracture toughness of 8.8 MPa· m1/2.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2011年第3期743-747,共5页
Journal of Synthetic Crystals
关键词
凝胶注模
氮化硅
粘度
力学性能
gel-casting
Si3N4
viscosity
mechanical properties
