La_(2)O_(3)-Y_(2)O_(3)复掺制备高强韧Al_(2)O_(3)陶瓷基板

摘要

Al_(2)O_(3)作为应用最广的陶瓷基板,优异的力学强度、韧性与导热性能是确保其安全可靠服役的前提。稀土金属氧化物(La_(2)O_(3)、Y_(2)O_(3))掺杂是提升Al_(2)O_(3)陶瓷力学性能的有效方法,然而,单一掺杂的强化效果有限,因此,采用La_(2)O_(3)-Y_(2)O_(3)复掺的方法以望进一步提升Al_(2)O_(3)陶瓷基板的抗弯强度与断裂韧性,并在此基础上探讨了La_(2)O_(3)-Y_(2)O_(3)复掺对Al_(2)O_(3)陶瓷热导率的影响规律。采用流延工艺分别于1550℃、1600℃保温2 h制得了Al_(2)O_(3)陶瓷,研究了烧结温度和La_(2)O_(3)/Y_(2)O_(3)掺量之比对Al_(2)O_(3)陶瓷物相组成、显微结构、力学-热学性能的影响,研究结果表明:当烧结温度为1550℃时,随着La_(2)O_(3)/Y_(2)O_(3)掺量之比的降低,Al_(2)O_(3)陶瓷的热导率逐渐增大,而其抗弯强度和断裂韧性呈先上升后下降的变化趋势,4 wt.%La_(2)O_(3)-1wt.%Y_(2)O_(3)复掺制得的Al_(2)O_(3)陶瓷最高抗弯强度为(682.24±41.51)MPa、最高断裂韧性为(5.58±0.56)MPa·m^(1/2),且其热导率较5 wt.%La_(2)O_(3)单掺试样高20.3%;当烧结温度为1600℃时,随着La_(2)O_(3)/Y_(2)O_(3)掺量之比的降低,Al_(2)O_(3)陶瓷的热导率逐渐增大,而其抗弯强度和断裂韧性逐渐减小,即掺加5 wt.%La_(2)O_(3)的Al_(2)O_(3)陶瓷(5:0-1550℃)最高抗弯强度为(629.57±31.15)MPa、断裂韧性为(5.71±0.34)MPa·m^(1/2)。由上述两个烧结温度获得的最优强度-韧性试样的性能对比可知,La_(2)O_(3)-Y_(2)O_(3)复掺的强化效果与烧结温度密切相关,4:1-1550℃试样的热导率与弯曲强度分别较5:0-1600℃试样高5.6%、8.4%,说明La_(2)O_(3)-Y_(2)O_(3)复掺有利于低温烧结制备力学-热学综合性能优异的Al_(2)O_(3)陶瓷。