Experimental Study of Hybrid Metal Matrix Aluminum Composite AA7075 SiC TiB2 Foam and its Characterization

Abstract

The automotive industry is increasingly focusing on lightweight materials with high newlinestrength-to-weight ratios to address challenges related to fuel consumption and newlineenvironmental emissions. Metal matrix composites (MMCs) and their foams, known for newlinetheir superior properties over traditional metals and monolithic materials, have emerged newlineas promising solutions. The aim of this thesis is to investigate the physical, newlinemicrostructural, and mechanical behavior of porous Al-SiC-TiB2 hybrid composite foam newlinewith varying wt.% of foaming agent and wt.% of primary reinforcement SiC in the newlineAA7075 Al-alloy metal matrix. The matrix material is made of the AA7075 alloy, which newlineis known for its applications in crash absorption and structural materials, serves as the newlinematrix material. Silicon carbide (SiC) is used as primary reinforcement and titanium newlinediboride (TiB2) as secondary reinforcement. SiC is chemically compatible with newlinealuminium and establishes a strong connection with the matrix without accumulating an newlineintermetallic phase and therefore the enhancement of the mechanical properties of the newlinecomposite will not be affected. TiB2 reveals outstanding features such as a high melting newlinepoint of 3,230 °C, high hardness, a high elastic modulus, and good thermal stability. TiB2 newlineceramic particles do not react with molten aluminum. Therefore, it avoids the formation newlineof brittle products at the interfaces of reinforcement and matrix. TiB2 particles enhance newlineexpansion in the foam without affecting foam stabilization, and these exceptional newlineproperties make SiC and TiB2 good choices as primary and secondary reinforcement. newlineTotally, three types of products were prepared to study the charactersisation. newlineFirstly, Al-SiC-TiB2 hybrid composites were formed with different wt. % of SiC and 3 newlinewt. % of TiB2. Later, Al-SiC composite foam was prepared with varying wt % of newlinefoaming agent. Lastly, Al-SiC-TiB2 hybrid composite foam was prepared with varying newlinewt % of primary reinforcemnt (SiC). From each product, specimens were prepared for newlinevarious investigations as mentioned below. newlineFor hybrid composites (product-1), the newline