Research on the Secondary Forgeability of High Volume Fraction Whisker Reinforced Aluminum Matrix Composites of Original Squeeze Casting

Shucong Xu,Lin Yuan,Lei Wang,Fuchang Xu,Debin Shan,Bin Guo,Jinyu Li,Zhenzhu Zheng

doi:10.3390/ma14237261

Shucong Xu, Lin Yuan + Show 6 more

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https://doi.org/10.3390/ma14237261

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Journal: Materials	Publication Date: Nov 27, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: Harbin Institute of Technology

Abstract

The poor formability of high volume fraction whisker reinforced aluminum matrix composites of original squeeze casting is an important factor restricting its further development and application. Currently, there are no reports on the secondary forgeability of aluminum matrix composites of original squeeze casting, although some papers on its first forgeability are published. The secondary forgeability is very important for most metals. This study aims to investigate the secondary forgeability of aluminum matrix composites. In this study, the secondary upsetting experiments of 20 vol% SiCw + Al18B4O33w/2024Al composites, treated by the original squeeze casting and extrusion, were carried out. The first upsetting deformation is close to the forming limit, the secondary upsetting deformation under the same deformation conditions was carried out to investigate the secondary forgeability. The experimental results show that, unlike aluminum alloys, the 20 vol% SiCw + Al18B4O33w/2024Al composites at the original squeeze casting and extrusion states have no secondary forgeability due to the whisker rotating and breaking during the secondary upsetting. The high volume fraction whisker reinforced aluminum matrix composites of original squeeze casting cannot be formed by the multiple-forging method since the cavities and cracks caused by whisker fracture continue to expand during secondary processing, which leads to further extension of macroscopic cracks.

Highlights

Metal matrix composites (MMCs), especially those based on light metals such as aluminum alloys, have become an indispensable lightweight structural material in hightech areas such as defense aerospace and military equipment due to its advantages of light mass, high strength, well thermal stability, wear resistance and low thermal expansion coefficient [1,2,3,4,5,6,7,8,9,10,11,12]
Leng et al [30] added graphite with different volume fractions and particle sizes, SiC/Gr/Al composites were prepared by squeeze casting, the results show that the elastic modulus of the composites tends to decrease with the increasing of volume fraction and particle size of graphite
This paper studies the forging deformation behavior of 20 vol% SiCw + Al18B4O33w/ 2024Al composites, explores the secondary forgeability of whisker-reinforced 20 vol% SiCw + Al18B4O33w/2024Al composites of original squeeze casting, and provides a reference for the design of the thermoplastic forming process for high volume fraction whiskerreinforced aluminum matrix composites of original squeeze casting

Summary

Introduction

Metal matrix composites (MMCs), especially those based on light metals such as aluminum alloys, have become an indispensable lightweight structural material in hightech areas such as defense aerospace and military equipment due to its advantages of light mass, high strength, well thermal stability, wear resistance and low thermal expansion coefficient [1,2,3,4,5,6,7,8,9,10,11,12]. Aluminum matrix composites have poor forgeability and a narrow forging temperature range. Deformation of composites is affected by matrix, reinforcement and strain rate [20]. During the plastic deformation process, the reinforcement added to the aluminum matrix composite will fracture due to its brittleness and hardness. Microcracks will be induced in the matrix, which reduces the thermoplastic deformation ability of the aluminum matrix composite [21]

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