Study to Addition of Graphene on the Microstructure and Mechanical Property of Nickel Based Super Alloy by Brazing

• Main Authors: Syu, Heng-Yao, 許恆耀
• Other Authors: Li, Yi-Kang
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/parj3f

碩士 === 大葉大學 === 醫療器材設計與材料碩士學位學程 === 105 === Nickel-based superalloy is the major material of turbine engine. During its manufacturing process, vacuum brazing technology is usually applied to ensure the excellent quality of weldments. Through adding nano-graphene to the filler metal and changing the volume of addition, this study discusses its influence on the microstructures and mechanical properties of Inconel 718 weldment. Filler metal contact angle test the contact angle of less than 90 degrees, filler metal and base metal nickel-based superalloy Inconel 718 showed good affinity. The result finds out that there are continuous intermetallic compounds gathering in the original brazed seam with high hardness value. However, after adding the graphene, the intermetallic compounds become equally distributed in the brazed seam, which means graphene has effect on the homogenization of brazed seam. Besides, the hardness value of the brazed seam center has sharply reduced to a level close to the base metal. If the volume of addition reaches 0.07 wt.%, there will be holes forming in the graphene brazed seam; if it is 0.03 wt.%, the maximum shear strength of the graphene weldment will be about 390.8 MPa, increasing by nearly 3%. Moreover, adding a little graphene also has effect on narrowing the width of brazed seam; if it is 0.07 wt.%, the maximum thermal conductivity of the graphene weldment will be about 22.7 W/m.k, increasing by nearly 242%