Effect of Zirconium Addition on Microstructure and Mechanical Properties of Inconel 713LC Superalloy

• Main Authors: Chia-Cheng Liu, 劉家成
• Other Authors: 王錫九
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/668572

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 106 === Inconel 713LC superalloy has low manufacturing cost and excellent mechanical properties at temperature below 700 ℃. While it has been applied widely as Diesel cars’ turbocharger, Inconel 713LC superalloy does not have good performance in gasoline cars, especially at high temperature. Therefore, the main purpose of this research is to enhance the tensile strength at high temperature by adding Zirconium in Inconel 713LC, and to develop alloy which is appropriate for gasoline cars. In addition, this research studies the effect of Zirconium addition on microstructure and mechanical properties of Inconel 713LC superalloy. The concentration of Zirconium (Zr) in this study is between 0.07-0.19 wt%. The Zr atoms would dissolve into carbides, which was analyzed by EDS mapping and EPMA, and altered the morphology of carbides from script-like to discontinuous particle-like. Carbides could enhance the strength of grain boundaries, so they would prevent grain boundary sliding at high temperature. However, the incoherent carbides would be the crack initiation during tensile test, and moreover, the continuous script-like carbides in Inconel 713LC (without Zr addition) let the cracks grow rapidly. Thus, the morphology of carbides dominates the strength at high temperature of Inconel 713LC alloy. With Zr addition, it would form discontinuous particle-like carbides, and improved the high temperature strength. This study concluded Inconel 713LC superalloy with Zr addition could strengthen the tensile properties at 982 ℃. The 0.19 wt% of Zr condition had the best high temperature tensile properties among all the specimens, in comparison with the base Inconel 713LC superalloy (Zr 0.07 wt%), the U.T.S. had enhanced 13.5%; the Y.S. had enhanced had enhanced 14.4%; the elongation had improved 121.3%.