Experimental and Numerical Study on Microstructure and Mechanical Properties of Ti-6Al-4V/Al-1060 Explosive Welding

Abstract

The aim of this paper is to study the microstructure and mechanical properties of the Ti6Al4V/Al-1060 plate by explosive welding before and after heat treatment. The welded interface is smooth and straight without any jet trapping. The disturbances near the interface, circular and random pores of Al-1060, and beta phase grains of Ti6Al4V have been observed by Scanning electron microscopy (SEM). Heat treatment reduces pores significantly and generates a titanium-island-like morphology. Energy dispersive spectroscopy (EDS) analysis results show that the maximum portion of the interfacial zone existed in the aluminium side, which is composed of three intermetallic phases: TiAl, TiAl2 and TiAl3. Heat treatment resulted in the enlargement of the interfacial zone and conversion of intermentallic phases. Tensile test, shear test, bending test and hardness test were performed to examine the mechanical properties including welding joint qualities. The results of mechanical tests show that the tensile strength and welding joint strength of the interfacial region are larger than one of its constituent material (Al-1060), the microhardness near the interface is maximum. Besides, tensile strength, shear strength and microhardness of heat treated samples are smaller than unheat treated. Smooth particle hydrodynamic (SPH) method is used to simulate the transient behaviour of both materials at the interface. Transient pressure, plastic deformation and temperature on the flyer and base side during the welding process were obtained and analyzed. Furthermore, the numerical simulation identified that almost straight bonding structure is formed on the interface, which is in agreement with experimental observation.

Impact Welding of Materials

“…However, significant differences were found for the upper limit. In turn, a coupled experimental/numerical work focused on studying the microstructure and the mechanical properties of titanium/aluminium explosion welds before and after being submitted to heat treatment was developed by Mahmood et al [2]. According to the authors, aluminium-titanium IMCs were formed at the weld interface, but these phases did not affect the weld strength.…”

Investigation of forming limit diagram and mechanical properties of the bimetallic Al/Cu composite sheet at different temperatures which fabricated by explosive welding

“…Also, the author conducted bending and tensile-shear tests and showed that no fracture or separation happened in the bonding interface of the layers which illustrates that the explosive welding process is an appropriate way to bond the aluminum and copper layers. Mahmood et al 27 investigated the mechanical properties and microstructure of the aluminum/titanium explosively welded bimetallic sheet before and after the heat treatment. They found out that the pores at the interface of the layers are less in the specimen after heat treatment.…”

Welding Window: Comparison of Deribas’ and Wittman’s Approaches and SPH Simulation Results

“…The majority of recent studies devoted to numerical simulation of high-velocity impact welding consider only few collision regimes providing only a limited understanding of the bonding phenomena [16][17][18]. Besides, most of the currently existing SPH studies on high-velocity impact welding simply state the fact of good agreement between the simulation results and experimentally observed interface.…”