Open AccessThe Effect of Boron and Zirconium on Microstructure and Stress-Rupture Life of Nickel-based Superalloy ATI 718Plus
Author(s) -
Seyed Ali Hosseini,
S.M. Abbasi,
Karim Zanganeh Madar
Publication year - 2015
Publication title -
metallurgical and materials engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.161
H-Index - 2
eISSN - 2812-9105
pISSN - 2217-8961
DOI - 10.30544/72
Subject(s) - materials science , superalloy , metallurgy , microstructure , zirconium , carbide , boron , alloy , boron carbide , grain boundary , vacuum induction melting , nickel , chemistry , organic chemistry
The effects of boron and zirconium on the microstructure, hardness and stressrupture life of the nickel-based superalloy ATI 718Plus were investigated in this study. Four alloys with different percentages of boron (0.005-0.01 wt.%) and zirconium (0-0.1 wt%) were cast through a vacuum induction melting furnace and then were rolled. The microstructural studies indicated an increased percentage of δ phase, carbide precipitates and twins in the presence of zirconium. The percentage of carbide (boron carbide) precipitates was increased and the solidification range of the alloy was decreased in the presence of boron in the composition. Furthermore, the results obtained from the hardness and stress-rupture tests showed the significant role of both elements in increasing hardness and improved rupture life of the alloy. The maximum rupture life was observed in the alloy which contained the highest percentages of boron and zirconium in its composition. This can be attributed mainly to the increased percentage of δ phase on grain boundaries and their enhanced high-temperature strength.