【摘要】 采用光学显微镜和SEM研究了热处理对定向镍基高温合金DZ951组织的影响。结果表明:选择合适的热处理工艺,能使铸态合金中较大的错配度减小甚至消失。固溶温度越高,γ′相的尺寸越大。在1200℃及其以上温度固溶处理时,γ′才能完全固溶于基体。固溶温度相同时,随着保温时间的延长,γ′相的尺寸增大。在1220℃固溶后进行时效处理,随着时效温度的升高,析出γ′相的尺寸增大。时效温度越高,γ′相的长大趋势越明显。合金经固溶处理和二级时效处理后,可获得两种尺寸的γ′相。更多还原

【Abstract】 Influence of heat treatment on the microstructure of directionally solidified DZ951 nickel base superalloy was investigated by optical microscope and SEM. The results show that the mismatch of as-cast alloy can be decreased or diminished if a reasonable heat treatment procedure is chosen. The size of γ ′ phase can be enlarged with the increase of solution temperature. The primary γ ′ phases can be completely soluble into the matrix above 1200℃. The size of γ ′ phase increases with the increase of the solution time at the same solution temperature. The coarsening γ ′ phase is precipitated when the alloy is aged at elevated temperatures and the size of γ ′ enlarges with the increase of temperature. The size of precipitated γ ′ phase enlarges with the increase of age temperature after solution treatment at 1220℃. The increasing trend of γ ′ phase is more obvious when the age temperature is higher. The γ ′ phases with two kinds of sizes can be achieved after the solution and the double ages.更多还原