Abstract: To solve the bottleneck problems of high sintering temperature and low mechanical strength of calcium hexaluminate (CA₆)-magnesium aluminate spinel (MA) composite materials,CA₆ powder,MA spinel powder and ρ-Al₂O₃ powder were used as raw materials to prepare CA₆-MA composite materials by heat treating at 1 600 ℃ for 5 h.The effects of the MA powder addition (the total mass fraction of CA₆ powder+MA powder was fixed at 100%,and the mass fractions of MA powder were 10%,30%,50% and 100%,respectively) and ρ-Al₂O₃ addition (10%,50%,70%,100%,150% and 200% of the total mass of CA₆ powder+MA powder) on the microstructure and properties of the materials were investigated.The results show that:(1)increasing the MA powder addition is beneficial to improving the densification of materials;(2)increasing the ρ-Al₂O₃ powder addition can improve the density and strength of the materials;when the MA powder addition is 50% and the ρ-Al₂O₃ powder addition is 150%,the sample exhibits the optimal comprehensive properties,with bulk density of 2.80 g·cm^-3,apparent porosity of 26.7%,linear shrinkage of 18.4%,cold modulus of rupture of 72.5 MPa,and cold compressive strength of 510 MPa.

Key words: CA₆-MA composite materials, cold compressive strength, pore size distribution, microstructure

摘要： 为解决六铝酸钙-镁铝尖晶石复相材料烧结温度高、力学强度低的瓶颈问题,以六铝酸钙(CA₆)粉、镁铝尖晶石(MA)粉和ρ-Al₂O₃粉为原料,经1 600 ℃保温5 h热处理制备CA₆-MA复相材料。研究MA粉的添加量(固定CA₆粉+MA粉总质量分数为100%,MA粉的质量分数分别为10%、30%、50%、100%)和ρ-Al₂O₃粉添加量(CA₆粉+MA粉总质量的10%、50%、70%、100%、150%、200%)对该材料显微结构和性能的影响。结果表明:提高MA粉的添加量有助于提高材料的致密化程度,提高ρ-Al₂O₃粉的添加量可以提高材料的致密度和力学强度,当MA粉的添加量为50%(w)、ρ-Al₂O₃粉的添加量为150%(w)时,试样的综合性能最佳,体积密度为2.80 g·cm^-3,显气孔率为26.7%,线收缩率为18.4%,常温抗折强度为 72.5 MPa,常温耐压强度为510 MPa。

关键词: CA₆-MA复相材料, 常温耐压强度, 孔径分布, 显微结构