Anisotropic FCGR behaviour in hot-rolled Mg-3Al-0.5Ce alloy

作     者：Prakash C.Gautam Somjeet Biswas Prakash C.Gautam;Somjeet Biswas

作者机构：Light Metals and Alloys Research LabDepartment of Metallurgical and Materials EngineeringIndian Institute of Technology KharagpurKharagpurWest Bengal 721302India Institut für Metallkunde und Materialphysik(IMM)Rheinisch-Westfälische Technische Hoschule Aachen52074 AachenGermany 

出 版 物：《Journal of Magnesium and Alloys》 (镁合金学报（英文）)

年 卷 期：2024年第12卷第7期

页      面：2985-3002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：support provided by the Science and Engineering Research Board(Ref.no.:ECR/2016/000125) Department of Science and Technology,Government of India.SB acknowledges the funding by Alexander von Humboldt Foundation,Germany 

主　　题：Fatigue crack growth rate(FCGR) Magnesium(Mg) Intermetallics Extension twins Crack closure 

摘      要：In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and transverse direction(TD).The FCGR tests were conducted at a constant load ratio(R=0.1)and maximum stress intensity factor(KMax=15.6 MPa√m)to investigate the crack closure *** both constant R and KMax conditions:(i)the load-displacement curves for every loading cycle were linear for a_(n)∥ to RD and TD,indicating no crack closure;(ii)the FCGR was found to be lower for an∥RD than an∥TD over the entire stress intensity factor range(△K).The hot-rolled sample contained long-aligned Al11Ce3 intermetallic phase within grain boundaries that are elongated along *** the FCGR test,{10.12}extension twins(ET)with lamellae∼⊥and c-axis∼∥to these elongated intermetallics along RD developed irrespective of the notch *** the loading cycle,these intermetallics along RD generate back-stresses,reducing the in-plane tensile stress∼||and∼⊥to crack-tip to∼0 for a_(n)∥to RD and TD,***,lenticular ET∼||⊥and∼||,with c-axis∼||and∼⊥to crack path activates,leading to trans and inter lamellar crack for anto RD and TD,respectively,and anisotropic *** crack in a_(n)∥RD reduces the FCGR due to plastic energy dissipation as perceived by comparatively more geometrically necessary boundaries(GNBs).On the other hand,faster FCGR was obtained for a_(n)∥TD due to interlamellar ***,the crack growth through the matrix-ET interfaces was favoured due to strain *** Fractography for a_(n)∥RD shows smaller elongated grooves along crack propagation,which indicates crack ***,larger elongated grooves for a_(n)||TD indicated easy crack propagation due to favourable interlamellar crack.