Fracture energy evaluation on 7075-T651 aluminum alloy welds determined by instrumented impact pendulum

作     者：R.R.AMBRIZ D.JARAMILLO C.GARCIA F.F.CURIEL R R AMBRIZ;D JARAMILLO;C GARCA;F F CURIEL

作者机构：Instituto Politécnico Nacional CIITEC-IPNCerrada de Cecati S/N Col.Sta.Catarina C.P 02250AzcapotzalcaDFMexico Mechanical and Aerospace EngineeringCarleton University1125 Colonel By DriveOttawaONK1S 5B6Canada Universidad Autónoma de Coahuila(UAdeC)Facultad de MetalurgiaCarr 57Km 5MonclovaCoahuilaMexico 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2016年第26卷第4期

页      面：974-983页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：CONACy T (project CB 177834) SIP-IPN for the funds given to conduct this research 

主　　题：7075-T651 welded joint instrumented Charpy pendulum force-time curve fracture energy dynamic yield strength 

摘      要：By using an instrumented impact pendulum, the force versus time curves of 7075-T651 aluminum welds were obtained from standard Charpy-V samples. Considering the force-time curves and constant impact velocity, the fracture energies for different zones were quantified. A fracture energy improvement for the HAZ(33.6 J) was observed in comparison with the weld metal(7.88 J), and base metal(5.37 J and 7.37 J for longitudinal and transverse directions, respectively). This toughness increment was attributed to the microstructural transformation caused by the thermodynamic instability of η′ precipitates during the welding. Fracture energy for weld metal was higher than that for base metal, probably due to pores created during solidification. Regarding the dynamic yielding force obtained from the force-time curves, an approximation to the dynamic yield strength for weld, HAZ and base metal was determined. Fracture surfaces revealed an intergranular failure for base metal in longitudinal direction, whereas a predominately brittle failure(cleavage) with some insights of ductile characteristics was observed for the transverse direction. In contrast, a ductile failure was observed for weld metal and HAZ.