Bending failure behavior of aluminum foam sandwich based on transient liquid phase bonding method

Abstract

Aluminum foam sandwich structure （aluminum foam sandwich, AFS） not only has the excellent characteristics of aluminum foam lightweight, damping and shock absorption, energy absorption and protection, but also can solve the problems of low strength and easy damage of single aluminum foam, so it has a broad application prospect in aerospace, automobile manufacturing, rail transportation, precision machine tools and other industrial fields. In this paper, based on the melt foaming method, an aluminum foam sandwich structure with the size of 80 mm×80 mm×18 mm was successfully prepared using pure TA2 as the panel and Al-2Ca alloy as the foaming base material, and a large number of uniform pores were observed in the foam core, of which the polyhedral pores occupied a large area. A binding interface with an average thickness of 7.5 μm was observed between the panel and the core layer，where the elements diffused at the binding layer and existed in the form of intermetallic compounds. The bending test results show that the load curves of sandwich structures with different densities show three distinct areas: linear elastic zone, rapid load drop zone and flatform zone. The maximum peak load and yield strength of the sandwich structure are 1120.5 N and 15.64 MPa respectively. The bending strength of AFS materials increases with the increase of density and the decrease of core porosity. When the bending degree is 15 mm and the AFS density increases by 15.9%, the bending energy absorption WEA and WSEA increase by 3.59 and 3.22 times respectively. In the process of bending test, the failure modes are composed of compressive compaction deformation of aluminum foam core layer, shear and cracking of core material, bending deformation and peeling failure of TA2 panel, and various failure modes of AFS material are formed under the joint action of different stresses at different positions of the sample.

Keywords

• aluminum foam sandwich structure
• ta2 panel
• bending performance
• failure mode