Tensile Fracture Behavior of 2A14 Aluminum Alloy Produced by Extrusion Process

Yunpeng Meng,Hua Zhang,Jianfeng Fan,Lifei Wang,Xia Li,Xin Zhou,Huajun Mo

doi:10.3390/met12020184

Abstract

In this study, the tensile mechanical properties of a 2A14 aluminum alloy produced by extrusion were tested at room temperature to investigate the tensile fracture behavior. The results showed that the tensile fracture of the alloy was mixed intergranular and transgranular ductile fracture, as numerous coarse second-phase particles were distributed in a band along the loading direction, making it prone to microcracking. This was determined to be the main cause of fracture failure of the alloy. In addition, we observed large α-AlFeMnSi(Cu), Al(Fe,Mn)Cu, AlCuMgSi, and Al2Cu phases in the microstructure of the 2A14 aluminum alloy, and both Al2Cu second phase and precipitation-free phase zone (PFZ) at the grain boundaries were observed, which made the alloy susceptible to fracture failure and reduced the mechanical properties of the alloy.

Highlights

Aluminum alloys are commonly used to manufacture engineering parts for aerospace and transportation applications due to their excellent characteristics, such as low density, high strength, good processing properties, and electrical conductivity; they have a limited range of applications, as aluminum alloys lose strength at high temperatures [1,2]
Al-Cu alloys have high toughness and excellent mechanical properties at high temperatures [3,4]. Adding alloying elements such as Si and Mg to Al-Cu alloy can change the precipitation behavior of the alloy and improve its mechanical properties. 2A14 aluminum alloy is a typical Al-Cu-Si-Mg forged aluminum alloy with high strength, heat resistance, and good thermoplasticity, and it is used for forging and drop-forged parts subjected to heavy loads [5,6,7,8,9]. 2A14 aluminum alloy is a heat-treatment-strengthening alloy, and its mechanical properties can be improved by heat treatment
Zhang et al [7] investigated the effect of the cooling rate on the residual stresses and tensile properties of 2A14 aluminum alloy forging through numerical simulations and quenching experiments

Summary

Introduction

Aluminum alloys are commonly used to manufacture engineering parts for aerospace and transportation applications due to their excellent characteristics, such as low density, high strength, good processing properties, and electrical conductivity; they have a limited range of applications, as aluminum alloys lose strength at high temperatures [1,2]. Reference the room-temperature tensile fracture behavior of 2A14 aluminum alloy. Because of its potential applications, it is essential to study the tensile fracture behavior of 2A14 aluminum alloy to ensure its safety. The distribution and size of the second phase will affect the fracture behavior of the alloy. It is important to systematically study the second phase of the 2A14 aluminum alloy after tensile fracture. We assessed the tensile fracture behavior of the 2A14 aluminum alloy at room temperature and determined the second phase type and distribution in its microstructure, and the precipitated phases and their effects on the properties of the alloy were assessed by energy dispersive spectrometer (EDS) and transmission electron microscope (TEM). The fracture mechanism of the 2A14 aluminum alloy provides a theoretical and practical basis for further research and development of 2A14 aluminum alloy materials

Experimental Section

Longitudinal Section Morphology of Fracture

Fracture Appearance

TEM Microstructure Analysis

Conclusions