Elaborating strengthen mechanism of Pt-Ir solid solution superalloy at finite temperature  

作　　者：Wei Yu Xiao-Yu Chong Yun-Xuan Zhou Meng-Di Gan Ying-Xue Liang Yan Wei Ai-Min Zhang Chang-Yi Hu Xing-Yu Gao Li Chen Hai-Feng Song Jing Feng 

机构地区：[1]Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming,650093,China [2]Yunnan Precious Metals Laboratory Co.LTD,Kunming,650106,China [3]Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing,100088,China

出　　处：《Rare Metals》2024年第3期1243-1256,共14页稀有金属（英文版）

基　　金：financially supported by the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(No.202102AB080019-1);Yunnan Fundamental Research Projects(Nos.202101AW070011 and 202101BE070001015);Yunnan Major Research and Development Plan(No.202203ZA080001);the Central guidance for Local Projects(No.202307AA110003);Yunnan laboratory project(YPML20220502157);the Major R&D Project of Yunnan Province(No.202302AB080021);the Major R&D Project of Yunnan Precious Metals Laboratory Co.,Ltd(No.YPML-2023050205)。

摘　　要：Pt-Ir alloy is potential superalloys used above 1300℃because of their high strength and creep resistance.However,the ductility of Pt-Ir alloy has rapidly deteriorated with the increase of Ir,resulting in poor machinability.This work quantitatively evaluated the solid solution strengthening(SSS)and grain refinement strengthening(GRS)of Pt-Ir alloy using first-principles calculations combined with experimental characterization.Here,the stretching force constants in the second nearest neighbor region(SFC^(2nd))of pure Ir(193.7 eV·nm^(-2))are 3.40 times that of pure Pt(57.0 eV·nm^(-2)),i.e.,the interatomic interaction is greatly enhanced with the increase of Ir content,which leads to the decrease of ductility,and modulus misfit plays a dominant role in SSS.Then,the physical mechanisms responsible for the hardness(H_(V))of Pt-Ir alloy,using the power-law-scaled function of electron work function coupled SSS and GRS,are attributed to the electron redistribution caused by different Ir content.Furthermore,a thorough assessment of the thermodynamic characteristics of Pt-Ir binary alloy was conducted,culminating in development of a mapping model that effectively relates enmposition,temperature and strength.The results revealed that the compressive strength incrcases with the Ir content,and the highest strength was observed in Pt_(0.25)Ir_(0.75).This study provides valuable insights into the Pt-Ir alloy system.

关 键 词：Elastic properties PHONON Solid solution strengthen Force constants CALPHAD 

分 类 号：TG132.3[一般工业技术—材料科学与工程]