Densification Mechanism for the Precursor of AFS under Different Rolling Temperatures

Abstract

The effect of rolling temperature on the precursor of aluminum foam sandwich (AFS) prepared by powder metallurgy through Pack Rolling method is investigated in this work. The cross-section along rolling direction of the precursors was observed. It was found that periodic corrugated morphology with micro-cracks on the composite interface as well as cracks and micro-holes among core powder particles emerged abundantly at room temperature rolling. These defects degraded with increasing rolling temperature and completely disappeared when the rolling temperature reached 400 °C. Combining with foaming ability of these precursors, the densification mechanism of core powders was discussed. Powder particles deformed with difficulty at low rolling temperature; the gap between them cannot be effectively filled through their plastic deformation. Fracture occurred in powder core layer during co-extension with the outer panel and was partly embedded by it, resulting in corrugated composite morphology at the interface. The precursors of high density and excellent bonding interface were prepared at the rolling temperature of 400 °C. A more suitable foaming condition was determined.

Fatigue of an Aluminum Foam Sandwich Formed by Powder Metallurgy

“…In this paper, the AFS was prepared by the powder metallurgy method [ 26 ]. The specific operation process was as follows.…”

“…At present, scholars are more concerned with an AFS prepared by the adhesive method, while the fatigue properties of an AFS made by the rolling composite-powder metallurgy method (hereinafter referred to as the powder metallurgy method) have rarely been reported. Based on the preparative study by Sun et al [ 26 ], this paper investigated the fatigue properties of an AFS made by the powder metallurgy method. The bonding interface was analyzed using optical microscopy, the fatigue properties were compared with AFS prepared by the adhesive method, and the fatigue fracture mode was investigated.…”

Interfacial Reactions between AlSi10 Foam Core and AISI 316L Steel Sheets Manufactured by In-Situ Bonding Process

“…the foaming process [14]. In this case, the expansion of the foam occurs between sheets kept at a constant distance corresponding to the final one.…”

“…On the other hand, high production cost, problems of recycling and poor temperature resistance are the main drawbacks. To overcome such problems, an alternative processing in-situ method has been developed in which the joint occurs as a direct consequence of the foaming process [14]. In this case, the expansion of the foam occurs between two metal Metals 2021, 11, 1374 2 of 7 sheets kept at a constant distance corresponding to the final one.…”

Three-Point Bending Behavior of Aluminum Foam Sandwich with Different Interface Bonding Methods

“…Previous studies comparing the performance of metallurgical-bonded AFS and glued AFS are relatively few. Based on the study of Zu et al [ 27 ], the metal-powder ratio, shell design, and rolling process [ 30 ] were optimized, and large-size metallurgical-bonded AFS were successfully prepared. In this paper, the metallurgical-bonding interface of AFS is characterized and analyzed, the interface peeling experiment of AFS is conducted, and the three-point bending performance of AFS under different interface bonding methods is compared.…”