王晓峰
,
赵九洲
金属学报
本文采用喷射成形和沉积坯热轧的方法成功制备了AZ91合金，测试了合金的力学性能，分析了合金的强化机理。实验结果表明：喷射成形的镁合金坯晶粒细小，组织均匀，第二相化合物Mg17Al12数量较少，表现出良好的塑性变形能力，道次变形量在20%左右，两次退火间的总变形量可以达到50%。经80%热轧变形后，合金完全致密化。变形使合金晶粒细化，力学性能显著提高。合金轧制后基体中仍保持很高的固溶度，经T5处理后，合金性能进一步提高。
关键词:
镁合金
,
Spray forming
,
Hot rolling
Guangmin LUO
材料科学技术（英文）
The graphitization behavior of ultrahigh carbon steels containing Si in hot rolling processes was investigated. The graphite stringers went mostly through the small pores and generally paralleled to the rolling direction. The influence of alloy elements on graphitization was estimated based on thermodynamics, which showed that Si content was important for graphitization. Graphite stringers nucleated at small pores and grew with carbon diffusion during hot rolling. Alloy contents, pores and hot deformation at γ+Fe3C phase range were the key factors for the formation of graphite. The probable effect of deformation on graphite formation during hot rolling was discussed in this paper.
关键词:
Graphitization
,
null
,
null
,
null
Jiuzhou ZHAO
,
Dongming LIU
,
Hengqiang YE
材料科学技术（英文）
In order to understand the solidification process of an atomized droplet and predict the fraction solidification of droplets with flight distance during spray forming, a numerical model based on the population dynamics approach is developed to describe the microstructure evolution under the common action of the nucleation and growth of grains. The model is coupled with droplets heat transfer controlling equations and solved for Al-4.5~wt~pct Cu alloy. It is demonstrated that the numerical results describe the solidification process well.
关键词:
Rapid solidification
,
null
,
null
,
null
