Product Code: ICAL06_1202

Mechanical Performance of Laser Deposition Repairing of IN 738 on Directionally Solidified Superalloy Blade
Authors:
Minlin Zhong, Tsinghua University; Beijing Peoples Republic of China
Xiaofeng Zhu, Tsinghua University; Beijing Peoples Republic of China
Wenjin Liu, Tsinghua University; Beijing Peoples Republic of China
Presented at ICALEO 2006

Development of cost-effective repair and rejuvenation processes for DS supperalloy blades are of great economic and technological meanings due to the high cost of the blades. Laser deposition has been proved to be a promising method to repair supperalloy components especially directionally solidified Ni-based superalloy blades, because of its relatively low heat input reducing the very high cracking susceptivity of the DS blades and DS characteristics even in the deposited layers by high temperature gradient epitaxial growth. This paper presents research work on the optimizing of parameters which is critical to achieve directional solidification, and mechanical performance of the directional solidified layers. A series of laser deposition experiments were carried out for optimized microstructure. After deposition, the standard heat treatment experiments were performed on the deposition layers. The microstructure characterization and phase identification were analyzed by SEM and XRD. The tensile test was carried out on a Gleebe 1500. Tensile test was performed both perpendicular and parallel to the solidified direction of the deposition layer and the base material (both before and after heat treatment). The temperature for tensile test is at room temperature, 600 and 900. The fracture surface morphologies were analyze and discussed in this paper. The results indicate that laser deposition can effectively repair the directional solidified In 738 Ni-based superalloy. The mechanical performance of the deposition layers can meet the need of practical use.