DZ125高温合金熔体超温处理定向凝固组织的演化规律  

Microstructure Evolution of DZ125 Superalloy Directionally Solidified with Melt Superheating Treatment

作　　者：张军[1] 杨敏[1] 王常帅[1] 刘林[1] 傅恒志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2009年第9期1108-1111,共4页Foundry Technology

基　　金：国家重点基础研究发展计划资助项目(批准号:2006CB605202)

摘　　要：在保持凝固界面温度梯度恒定的条件下,研究了DZ125高温合金熔体超温处理定向凝固组织的演化规律。实验结果表明,熔体超温处理对DZ125合金的定向凝固组织有着显著的影响。一次枝晶间距和二次枝晶间距均随着熔体超温处理温度的升高,呈现出先减小后增大的变化规律,并在超温处理温度为1 650℃处出现最小值。合适的熔体超温处理可以起到与提高凝固速率相同的作用,有效细化合金凝固组织,从而有利于降低合金元素偏析程度,减少甚至消除凝固缺陷,缩短热处理均匀化时间,提高合金的力学性能。With the constant temperature gradient of solidification interface, the microstructure evolution of DZ125 superalloy directionally solidified with melt superheating treatment is studied. The experiment results show that the melt superheating treatment has remarkable influence on the solidification microstructure. With the melt superheating temperature increased from 1 500℃ to 1 650 ℃ and to 1 750 ℃ respectively, the primary and the secondary dendrite arm spacing are all first decreased and then increased. When the melt superheating temperature is 1 650 ℃, the dendrite arm spacing reaches the minimum. It can be seen that the proper melt superheating treatment can lead to the effective microstructure refinement which can be obtained with the elevated solidification rate. Thus, the segregation degree of alloy elements can be reduced, the solidification defects can be eliminated, and the time of homogenization heat treatment was reduced, which improves the mechanical properties of alloys.

关 键 词：DZ125高温合金 定向凝固 熔体超温处理 凝固组织 

分 类 号：TG132.32[一般工业技术—材料科学与工程]