田口法研究3Y-TZP/TiN导电陶瓷材料最佳化制程

实验用田口法研究了添加30wt%氮化钛的钇稳定氧化锆基陶瓷材料(3Y-TZP/TiN)制造工艺.选择烧结方式、TiN粉末振荡时间、第一阶段保温时间及第二阶段烧结温度四个工艺参数作为控制因子,设计L9正交表进行实验规划.烧结后,检测试片断裂韧性、抗弯强度、硬度、相对密度及电阻值.最后通过变异数分析找出最佳参数,再进行实验验证.本研究得到的最佳化烧结工艺为:TiN粉末振动8 h,采用两步烧结法,第一阶段烧结温度1450℃,不保温,第二阶段烧结温度1150℃,保温20 h.结果显示,采用该工艺得到了抗弯强度平均值为736.75 MPa、断裂韧性为7.545 MPa.m1/2的氧化锆基导电陶瓷材料.研究发现,第一阶段保温时间对断裂韧性的影响程度最大,其次依次为烧结方式、TiN粒径大小及第二阶段保温温度.断裂韧性的微结构影响因子为四方相与单斜相数量的比值,当此值达到最高时,断裂韧性也达到最高值为9.275 MPa.m1/2.另外,添加30wt%TiN的氧化锆电阻率平均值为3.26 m.cm,可以进行电火花加工.

Optimal Process Parameters for 3Y-TZP/TiN Conductive Polycrystal by Taguchi Method

For the manufacturing of 3mol% Yttria-tetragonal Zirconia polycrystal(3Y-TZP) with 30wt% of Titanium Nitride(TiN)(3Y-TZP/TiN) powders,Taguchi method was used to selected the process parameters including sintering step variation,crushing time of TiN powder,the first step sintering duration and second step sintering temperature to be the controlling factors.The characterization features of sintered samples such as fracture toughness,flexural strength,hardness,relative density and electric resistance were explored through L 9 orthogonal array.By analysis of variance(ANOVA),the optimal parameter settings for each response factor were obtained and tested through confirmation experiments.The results indicate that the optimal process parameters contain 8h crushing time of TiN powder,two-steps sintering processes including the 1450℃ temperature with no duration for the first step and 1150℃ temperature and 20 h duration for the second step,and the average flexural strength of 736.75 MPa and fracture toughness of 7.545 MPa m 1/2 are obtained.In addition,the degree of the process parameter effects on the sintered samples is found in the series of the sintering duration of the first step,sintering step variation,size of TiN particles and the sintering temperature of the second step.Meanwhile,fracture toughness depends significantly on the ratio of tetragonal phase to monoclinic phase and attends to be 9.275 MPa.m 1/2 when the ratio is getting to the maximum.The average electric resistance for 3Y-TZP/ TiN is measured to be 3.26 m.cm.These samples can be electric-discharge machined.