Mechanical and microstructural analysis of Al-Al 2 O 3 /B4C hybrid composites

Mishra

Proceedings of the Institution of Mechanical Engineers, Part L:

2021

ZA-27 hybrid metal matrix composites reinforced with lamb bone ash (LBA) and boron carbide (B4C) were fabricated by employing stir casting route. Single-reinforced composite with 5 wt.% of LBA and hybrid composites reinforced with LBA/B4C in the ratio of (3.75:1.25, 2.5:2.5, 1.25:3.75) were developed. Composites were processed as per ASTM standards and subjected to physical characterization (density and porosity), microstructural characterization, and mechanical characterization (hardness, compressive strength, tensile strength, and impact strength). Microstructural studies of ZA-27 composites using a scanning electron microscope (SEM) revealed the uniform dispersion of reinforcements. X-ray diffraction (XRD) patterns and energy-dispersive X-ray spectroscopy (EDS) of the developed composites confirmed the existence of LBA and B4C particles in the matrix. The density of the composites declined, and porosity increased with the increment in B4C wt.% compared with base alloy. Mechanical properties like hardness, compressive strength, and tensile strength improved significantly in the case of hybrid composites than single-reinforced composite. Hardness, compressive strength and tensile strength of the hybrid composites increased to a maximum of 41.12%, 24.40%, 61.08% respectively compared to the base alloy, whereas single-reinforced composite showed maximum improvement of 19.26% (hardness), 11.16% (compressive strength), and 28.38% (tensile strength) compared to the base alloy. Ductility of the composites decreased with the addition of reinforcements. Impact strength of the composites showed a marginal reduction; however, the reduction was higher in the single-reinforced composite than hybrid reinforced composites. Fractured morphology showed dimples, cracks, tear ridges, and voids.

Section: Mechanical Characterizationmentioning

confidence: 99%

Microstructural and mechanical characterization of lamb bone ash and boron carbide reinforced ZA-27 hybrid metal matrix composites

Mishra

Proceedings of the Institution of Mechanical Engineers, Part L:

2021

“…However, despite their numerous advantages, conventional MMCs often exhibit certain limitations, such as limited fracture toughness, insufficient thermal conductivity, and a high coefficient of thermal expansion. To address these limitations and further optimize the properties, the concept of Hybrid Metal Matrix Composites (HMMCs) emerged [18,19].…”

Section: Introductionmentioning

confidence: 99%

Synergistic effects of cold rolling and age hardening on the hardness and tensile characteristics of AA6061 hybrid composites

Sadanand,

Sharma,

Prabhu

2024

Mater. Res. Express

The present study involves the fabrication of aluminium alloy 6061 matrix hybrid composites with varying weight fractions of silica sand and copper particles by employing the conventional stir casting method. The combined influence of age hardening (AH) and low temperature thermomechanical treatment (LTMT) on the hardness and tensile properties of AA6061 hybrid composites was investigated. The uniform dispersion of the particles in the matrix was confirmed by microstructure analysis and the improvement of Brinell hardness values. The composites exhibited higher tensile strength and hardness than the base alloy. The peak hardness and tensile strength at the peak aged condition of the hybrid composites were determined through the Vickers hardness and tensile test, respectively. Both AH and LTMT enhanced the properties of the hybrid composites, and a comparison between them revealed the best results for LTMT hybrid composites. The LTMT hybrid composite with 3 wt.% silica sand and 3 wt.% copper (3S3C) subjected to 12% rolling deformation and aged at 100 °C had the highest Vickers hardness and tensile strength of 144.26 HV and 290 MPa, respectively. The hardness and tensile strength of AA6061-3S3C hybrid composite subjected to LTMT in peak aged condition showed an improvement of 125 and 97%, respectively, compared with those of AA6061 alloy. Fracture surface analysis of the thermomechanical treated composites in peak aged condition showed a mixed mode of failure dominant with the ductile fracture.

“…The results indicated that the surface composite exhibited higher hardness and ballistic e ciency due to the dispersion strengthening mechanism induced by the reinforced particles. Gupta and Gupta [21] prepared Al-B 4 C/Al 2 O 3 hybrid composite using the stir casting route and reported enhanced mechanical properties and reduced porosity as compared to Al matrix and single reinforced metal matrix composites.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the effect of reinforcement compositions on the properties of Aluminum LM 25/h-BN/B 4 C hybrid composites

Katla,

2023

Preprint

This study investigates the effect of the compositions of hexagonal boron nitride (h-BN) and boron carbide (B4C) reinforcements on the properties of aluminum matrix composites (AMC). The compositions of both the reinforcements in the Aluminum LM 25(A 356) alloy metal matrix are varied from 0 to 10% by volume. Based on the mixture design of experiment, ten AMCs are fabricated with different reinforcement compositions by the stir casting process. The microstructure, density, porosity, and hardness of these AMCs are analyzed and compared with that of unreinforced base aluminum alloy to study the effects of reinforcement composition. Microstructure analysis revealed that the reinforcements were uniformly distributed in the matrix phase with minimal agglomeration for the composites with up to 6% reinforcements. The density was found to decrease with the increase in the reinforcements due to the presence of porosities in the matrix and the addition of low-density reinforcements. With the increase in the volume percentage of reinforcements in hybrid composites, there was an increase in hardness. BC10BN0 mono composites exhibited the highest hardness value of 78.8 BHN due to the presence of hard B4C ceramic particles, whereas BC10BN0 demonstrated the lowest hardness of 57.13 BHN because of the h-BN particles having lower hardness than B4C particles. Among the hybrid composites, BC5BN5 resulted in the highest hardness, which was 26.3% higher than the base aluminum alloy. From the desirability analysis, 94.194% of LM 25, 2.389% of h-BN, and 3.417% of B4C were found to be the optimal conditions for minimizing porosity and maximizing hardness. The hybrid aluminum matrix composites developed in the present study can be utilized for automobile and aerospace applications.