Single-crystal laser deposition of superalloys:: Processing-microstructure maps
Single-crystal laser deposition of superalloys:: Processing-microstructure maps
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DOI：
10.1016/s1359-6454(00)00367-0
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发表时间：
2001-04-02
期刊：
影响因子：
9.4
通讯作者：
Kurz, W
中科院分区：
文献类型：
--
作者：
Gäumann, M;Bezençon, C;Kurz, W
为了延长现代单晶（SX）高压高温燃气轮机叶片的寿命周期，裂纹或磨损部件的修复是人们非常感兴趣的问题。修复技术的成功关键取决于严密的过程控制，以确保SX修复。基于凝固理论，提出了一种外延激光金属成形工艺。本文提出了基于工艺图的任何SX修复过程控制所必需的重要概念，这些工艺图将预期的凝固组织和生长形态与加工条件联系起来。这些地图分两步获得。首先，阐述了局部凝固条件与凝固组织（即柱状或等轴状）之间的关系。其次，利用解析型磁通模型计算了局部凝固条件与激光加工参数的关系。通过两种方法的结合，获得了加工显微组织图，确定了SX生成和激光沉积修复的加工窗口。(C) 2001材料学报Elsevier Science Ltd.出版。
In order to extend the life cycle of modern single-crystal (SX) high-pressure high-temperature gas turbine blades, repair of cracked or worn parts is of great interest. The success of the repair technique depends critically on a close process control in order to ensure SX repair. Based on solidification theory a process called epitaxial laser metal forming (E-LMF) has been developed. This paper presents the important concepts necessary for any process control for SX repair based on processing maps which relate the expected solidification microstructures and growth morphologies to the processing conditions. These maps are obtained in two steps. Firstly, the relationships between local solidification conditions and the resulting solidification microstructures, i.e. columnar or equiaxed, art: formulated. Secondly, the local solidifiuation conditions as a function of the laser processing parameters are calculated with an analytical hear flux model. By a combination of both approaches, processing-microstructures map are obtained which define processing windows for SX generation and repair by laser deposition. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd.