Effect of Rotational Speed on Static and Fatigue Properties of Rotary Friction Welded Dissimilar AA7075/AA5083 Aluminium Alloy Joints

Abstract

In this work, rotary friction welding processes of dissimilar AA7075/AA5083 aluminium alloy rods with the diameter of 15 mm were performed at varying rotational speeds, typically 370 to 2500 rpm. The aim of this research is to improve mechanical properties, in particular, strength and fatigue performance of the weld joints. Several experiments including macro and microstructural examinations, Vickers microhardness measurements, tensile tests, fatigue tests and residual stress measurements were carried out. Results showed that at higher rotational speeds, typically 540 rpm or above, the dissimilar AA7075/AA5083 rotary friction weld joints revealed a static fracture in the AA5083 base metal side, indicating that the joint efficiency is more than 100%. It seemed that the best weld joint was achieved at the rotational speed of 1200 rpm, in which the friction heat was sufficient to form metallurgical bonding without causing excessive flash and burn-off. In such a condition, the fatigue strength of the weld joint was slightly higher than AA5083 base metal, but it was lower than AA7075 base metal. It was confirmed that the crack origin is observed at the interface followed by fatigue crack growth towards AA5083 side, and the growth of crack seemed to be controlled by microstructure and residual stress.

Effect of Heat Treatment on the Microstructure and Mechanical Properties of Rotary Friction Welded AA7075 and AA5083 Dissimilar Joint

“…Sasmito et al [ 19 ] investigated the static and fatigue properties of rotary friction welded AA7075/AA5083 at various rotational speeds. They reported that low rotational speed (370 rpm) was insufficient to generate the heat required for bond formation.…”

Microstructure and Mechanical Properties of Solid-State Rotary Friction Welded Inconel 713C and 32CrMo4 Steel Joints Used in a Turbocharger Rotor

“…The RFW method has been used for numerous applications, including drill pipes, piston rods, turbine discs, turbines for aircraft engines, steel truck axles, heat exchangers, and passenger car wheel rims [ 14 , 15 , 16 ]. The most commonly studied parameters of the rotary friction welding are temperature, axial force and pressure, rotation speed, and burn-off length [ 17 , 18 , 19 , 20 ].…”

Rotary Friction Welding of Polyetheretherketone Biopolymer Rods Using Variable Rotational Speed

“…As a result, PEEK is widely used in reinforcing rods. In general, the number of revolutions is constant during the welding process [15], such as 1125 rpm [16], 1350 rpm [17,18], 950 rpm [19], 650 rpm [20], 800 rpm [21], 1600 rpm [22,23], 1000 rpm [24], 1400 rpm [25], 1200 rpm [26], or 900 rpm [27]. This study proposes an innovative method for the RFW of PEEK polymer rods by varying the rotational speed.…”