摘要
比较了超高梯度定向凝固法（ＺＭＬＭＣ法）和普通定向凝固法（ＨＲＳ法）对ＤＺ２２合金的高温力学性能和组织的影响．结果表明：ＺＭＬＭＣ法大幅度地提高了合金的高温力学性能，９８０℃，２２０ＭＰａ条件下的高温持久寿命由７２ｈ提高到１６８ｈ；一次、二次枝晶臂间距λ１和λ２分别由１５０μｍ和５０μｍ．左右减小到６８μｍ和１６μｍ左右；元素的枝晶偏析得到抑制；合金显微组织的组成相γ′，（γ＋γ′）共晶，ＭＣ型碳化物的形态、大小和分布均发生了明显的变化；断口形貌，ＨＲＳ法为粗大的方形或近似圆形的韧窝。
his paper deals with mechanical properties and structure of superalloy DZ22 with zone melting and liquid metal cooling (ZMLMC) directional solidification process and high-rate solidification (HRS)process. Experimental results show that ZMLMC has more advantages compared with HRS. The average stress-rupture life of DZ22 at 980t and 220MPa increases from 72h to 168h. The primary and secondary dendritic arm spacing λ1 and λ2 of DZ22 decrease from 150μm and 50μm to 68μm and 16μm respectively.The microsegregation of elements is decreased. The morphology, size and distribution of γ', eutectic (γ+γ')and MC change obviously. Coarse cubic or round-like tough dimples appear in the fracture surface of HRS sample and fine round tough dimples in that of ZMLMC sample.
出处
《材料研究学报》
EI
CAS
CSCD
1996年第1期13-18,共6页
Chinese Journal of Materials Research
基金
国家自然科学基金
关键词
DZ22合金
枝晶特性
力学性能
定向凝固法
合金
ZMLMC process HRS process superalloy DZ22 dendritic characteristicfractograph
