Optimization of squeeze cast process parameters on mechanical properties of Al2O3/SiC reinforced hybrid metal matrix composites using taguchi technique

In the present technological environment, the aerospace industry needs cutting-edge materials not only to meet the requirements such as lower weight and higher values of strength and stiffness, but also to protect against electromagnetic interference. In this article, an attempt has been made to prepare Al6061 hybrid metal matrix composites reinforced with varying percentages of SiC, Al2O3, and fly ash particulates through a stir-casting route. As per ASTM standards, various tests have been conducted to know the density, tensile strength, yield strength, and hardness. Simultaneously, all the prepared composites are tested for electromagnetic interference (EMI) shielding effectiveness (SE) under the X band frequency with the help of a vector network analyzer. In order to identify the composite possessing good mechanical properties, as well as shielding effectiveness, a TOPSIS methodology has been employed in this work. The present study reveals that the proposed hybrid composite contains 5% of each reinforcement material which shows better mechanical properties as well as good shielding effectiveness.

Download Full-text

Effect of Reinforcements on Mechanical Properties of Nickel Alloy Hybrid Metal Matrix Composites Processed by Sand Mold Technique

Applied Science and Engineering Progress ◽

10.14416/j.asep.2020.11.001 ◽

2020 ◽

Vol 14 (1) ◽

Author(s):

Kumaraswamy Jayappa ◽

Vijaya Kumar ◽

Gange Gowda Purushotham

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Hybrid Composites ◽

Research Work ◽

Weight Percent ◽

Matrix Composites ◽

Hybrid Metal Matrix Composites ◽

Ni Alloy

Hybrid Metal Matrix Composites (HMMCs) have gained wide applications in aerospace, marine, and domestic areas because of its significant properties relative to external forces and enabling environment. In present research work, Ni-alloy selected as a matrix and Al2O3 of 40–80 μm and TiO2 of 1–5 μm were selected as reinforcements. The composites were prepared by keeping 9 wt. % of TiO2 as unvarying and Al2O3 is varied from 3 weight % to 12 weight % in steps of 3 weight %. Induction furnace is used for the casting of composites and mixing is done by using mechanical stirring at 160 rpm for a time period of 5 min. The prepared composites are then tested for their tensile and hardness as per the ASTM standards. The Scanning Electron Microscopy was used for microstructural study. From experimentation, it was observed that increment in the weight percentage of Al2O3 with constant TiO2 increases the mechanical properties of hybrid composites and proper stirring improves homogeneity in the composite material. The test results show that the addition of Al2O3 up to 9 weight percent increases in tensile strength compared to Ni alloy and tensile strength slowly decreases with the addition of Al2O3 and that the hardness values are directly proportional to the weight percent of the addition of Al2O3 / TiO2.

Download Full-text