作　　者： ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院粉末冶金国家重点实验室

出　　处： 《稀有金属材料与工程》 2004年第11期1143-1148,共6页

摘　　要： 通过对混合元素法 Ti-Fe 合金烧结过程中的膨胀/收缩行为、淬火态和烧结态显微组织的分析,研究了添加铁对混合元素法 Ti-Fe 合金的烧结行为和组织演化的影响。结果表明:铁元素对钛粉末的烧结行为的影响可分为 2 个阶段:(1)铁元素的扩散均匀化;(2)单相的 β-Ti(Fe)的烧结致密化。在升温速率为 5 K/min 和铁含量为 5w/%的情况下,铁元素在 Ti-Fe 系的第 1 共晶点(1 085℃)之前就完全固溶到钛基体中,瞬时液相并没有出现。添加铁元素促进了 Ti-Fe 合金的烧结致密化。随着铁含量的提高,原始 β 晶粒平均尺寸及片状 α 晶团(Colony)的平均尺寸略有增加,α 片的平均厚度急剧下降。铁的高扩散速率和铁的 β 相稳定效果是导致这些结果的主要原因。 Blended Elemental Powder Metallurgy, process is identified as one of the most promising production process for commercial uses of titanium alloys owing to the economical. efficiency and high degree of freedom in selection of alloy composition as well as microstructure design. The effect of iron on the sintering behavior and microstructure evolution of Ti-Fe alloys was investigated by analyzing their expansion/contraction behaviors and quenched and sintered microstructure of specimens. The effect of Iron on the sintering behavior of Ti powder was investigated from two aspects: (1) diffusional homogenization of iron; (2) densification of beta-Ti (Fe) phase. Under the present conditions (heating rate of 5 Kmin(-1) and iron content 5wt%), Fe dissolved thoroughly into the titanium matrix before the first eutectic temperature, potential liquid phase did not appear. Addition of iron can accelerate the sintering shrinkage of Ti-Fe alloys. With increasing iron content, the mean beta grain sizes and lamellar alpha colony increase slightly, while the mean thickness of lamellar alpha phase reduces greatly. These results attribute to high diffusion rate and beta stabilizing effect of iron.

关 键 词： 合金 混合元素法 烧结行为 组织演化

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]