Effect of Bimodal Grain Size Distribution on the Strain Hardening Behavior of a Medium-Entropy Alloy

作     者：Ibrahim Ondicho Bernard Alunda Fredrick Madaraka Melody Chepkoech Ibrahim Ondicho;Bernard Alunda;Fredrick Madaraka;Melody Chepkoech

作者机构：Department of Mechanical EngineeringDedan Kimathi University of TechnologyPrivate bag-10143Dedan KimathiNyeriKenya MaterialsDesignand Manufacturing(MADEMA)GroupDedan Kimathi University of TechnologyPrivate Bag-10143Dedan KimathiNyeriKenya Department of Mining and Minerals Processing EngineeringTaita Taveta UniversityP.O.Box 635-80300VoiKenya Department of Mechanical EngineeringHoward University23006th Street NWWashingtonDCUSA 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2021年第34卷第4期

页      面：465-475页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2019R1A2C1088535) 

主　　题：Metals and alloy Mechanical properties Microstructure High-entropy alloys Plastic deformation 

摘      要：The evolution of strain hardening behavior of the Fe_(50)(CoCrMnNi)_(50) medium-entropy alloy as a function of the fraction of recrystallized microstructure and the grain size was studied using the Hollomon and Ludwigson *** specimens under study were partially recrystallized,fully recrystallized with ultrafine-grained microstructure,and fully recrystallized with coarse *** yield strength decreases steadily as the fraction of recry stallized micro structure and grain size increases due to the recovery process and the Hall-Petch ***,the bimodal grain distribution was found to have a significant impact on strain hardening during plastic *** instance,the highest ultimate tensile strength was exhibited by a 0.97 μm specimen,which was observed to contain a bimodal grain ***,using the Ludwigson equation,the effect of the bimodal grain distribution was established from the behavior of K_(2) and n_(1) *** curves tend to show very high values in the specimens with a bimodal grain distribution compared to those that show a homogenous grain ***,the bimodal grain distribution contributes to the extensive Luders strain observed in the 0.97 μm specimen,which induces a significant deviation of the Hollomon equation at lower strains.