Fabrication of Aluminum Foam-Filled Thin-Wall Steel Tube by Friction Welding and Its Compression Properties.

Yoshihiko Hangai,Osamu Kuwazuru,Soichiro Kitahara,Takao Utsunomiya,Masaki Saito,Nobuhiro Yoshikawa

doi:10.3390/ma7096796

Abstract

Aluminum foam has received considerable attention in various fields and is expected to be used as an engineering material owing to its high energy absorption properties and light weight. To improve the mechanical properties of aluminum foam, combining it with dense tubes, such as aluminum foam-filled tubes, was considered necessary. In this study, an aluminum foam-filled steel tube, which consisted of ADC12 aluminum foam and a thin-wall steel tube, was successfully fabricated by friction welding. It was shown that a diffusion bonding layer with a thickness of approximately 10 μm was formed, indicating that strong bonding between the aluminum foam and the steel tube was realized. By the X-ray computed tomography observation of pore structures, the fabrication of an aluminum foam-filled tube with almost uniform pore structures over the entire specimen was confirmed. In addition, it was confirmed that the aluminum foam-filled steel tube exhibited mechanical properties superior to those of the ADC12 aluminum foam and steel tube. This is considered to be attributed to the combination of the aluminum foam and steel tube, which particularly prevents the brittle fracture and collapse of the ADC12 foam by the steel tube, along with the strong metal bonding between the aluminum foam and the steel tube.

Highlights

Aluminum foam is expected to be used as a shock absorber of automobiles and a sound absorber of building materials owing to its high energy absorption properties, sound insulation properties and light weight [1,2]
Only the temperature of the precursor was increased by the friction between the precursor and the rotating tool, and the generated heat did not transfer rapidly to the jig because of the gap between the precursor and the steel tube
The friction between the side of the tool and the plastic flow of the Aluminum foam (Al foam) precursor further increased the amount of heat

Summary

Introduction

Aluminum foam is expected to be used as a shock absorber of automobiles and a sound absorber of building materials owing to its high energy absorption properties, sound insulation properties and light weight [1,2]. It was demonstrated that the bonding between Al foam and dense materials further improves the performance of composites [7,10]. Adhesives were used for bonding between previously fabricated Al foam and dense materials [2,7]. It is considered that the composites fabricated using an adhesive cannot be used under high-temperature conditions [3] and have limited usage owing to the difficulty in recycling [3] and considerable environmental concerns [11]

Methods

Results

Conclusion