Role of Reinforcement Particle Size and Its Dispersion on Room Temperature Dry Sliding Wear of AA7075/TiB2 Composites

Aluminum alloy based metal matrix composites (AMCs) are widely accepted material in the aerospace, automotive, military, and defence applications due to lightweight and high strength. For tribological applications, high-performance wear-resistant materials like AMCs are the candidate materials. In this investigation, AA7075 based composites with different size TiB2 particles were fabricated using in-situ and ultrasound casting techniques (UST). The AMCs were tested using pin-on-disc tribo tester and the effects of different sized TiB2 particles on wear resistance of AA7075/TiB2 composites have been investigated. The wear resistance of AA7075/TiB2 composite fabricated using UST is found to significantly improve when compared to base alloy and also in-situ composite due to refinement in the particle size, reduced the agglomeration, and improved the distribution of TiB2 particles. The test results also revealed the existence of a mixture of mechanically mixed Al–Zn–Fe intermetallic alloy and oxides of these elements.

Synthesis and characterization of spent alumina catalyst and grinding sludge reinforced aluminium-based composite material

In this investigation, an attempt has been made to use the waste material in the fabrication of aluminium-based composite material. Waste spent alumina catalyst (SAC) generated from oil refinery industries has been considered as primary reinforcement particle. Waste grinding sludge (GS) produced from iron forging industry was used as secondary reinforcement material in the preparation of composite. Further, chromium (Cr) has been added to SAC and grinding sludge (GS) reinforced aluminium-based composite material to prevent grain growth as well as to control the grain structure of composite material. Experimental results concluded that by adding 4.5% of GS and SAC with 1.5% Cr in aluminium alloy, mechanical properties such as hardness, compressive strength and tensile strength were significantly improved. Hardness compressive strength and tensile strength was increased by 40.06%, 7.24% and 18.86%, respectively, with respect to the aluminium alloy. However, the reduction in toughness was observed. SEM results depicted uniform distribution of SAC and GS particles in Al/4.5% SAC/4.5% GS/1.5% Cr composite. Thermal expansion behaviour and corrosion weight loss of composite have been also investigated to observe the influence of reinforcement in the aluminium alloy.

Effect of Wettability and Uniform Distribution of Reinforcement Particle on Mechanical Property (Tensile) in Aluminum Metal Matrix Composite—A Review

There is a massive demand for low-weight high strength materials in automotive, space aerospace, and even structural industries in this present engineering world. These industries attract composites only because of their high strength, resistance to wear, and low weight. Among these composites, metal matrix composite finds wide applications due to its elevated properties, excellent resistance property, corrosion resistance, etc. The reinforcements exist in particles, fiber, and whiskers. Among the three, particles play an important role because of their availability and wettability with the metal matrix. Additionally, among the various metal matrices such as aluminum, magnesium, copper, titanium, etc., aluminum plays a vital role among metal matrices because of its cost, availability in abundance, and castability. Stir casting is the most inexpensive and straightforward composite fabrication technique among the prevailing techniques. Even though so many factors contribute to the elevated property of composites, metal matrix, and reinforcement phase, uniform distribution and wettability are essential factors among all the other factors. This review aims to develop a composite with elevated property in a cost-effective manner. Cost includes metal matrix, reinforcement, and processing technique. Various works have been tabulated to achieve the above objective, and analysis was carried out on tensile strength concerning microstructure. This review paper explores the challenges in composite fabrication and finds a solution to overcome them.

Experimental investigation on stir casting of a metal matrix composite material

In this article, Al7075 matrix with SiC as reinforcement particle was developed and the mechanical properties such as tensile strength, hardness, and impact strength was investigated. Aluminum is preferred as a matrix phase because Al alloys have low density and good ductility. Silicon carbide is chosen as a reinforcement phase due to its brittle and hard properties to enhance the wear properties. Mechanical properties of aluminum metal matrix have been tested at different temperatures and holding time. It shows an ultimate tensile strength of 121 N/mm2 at 800°C processing temperature and 20 mins of holding time. At a processing temperature of 850°C, it shows maximum hardness and impact strength. Among all the fabrication processes, stir casting is chosen because stir casting process is the simplest and cheapest for fabricating metal matrix composites (MMCs). Microelectronic and aerospace packaging industry requires a material with optimum hardness and impact strength to prevent the material from wear and impact during material handling. These MMCs will be a replacement for traditionally used materials such as W-Cu, BeO, and Kovar in packaging application.

EFFECT OF DEPOSITION TECHNIQUES OF REINFORCEMENT DURING FABRICATION OF AL-BASED SURFACE HYBRID MATRIX METAL MATRIX COMPOSITE

Several deposition methods have been proposed for pre-deposition of reinforcement particle for preparation of surface metal matrix composite by Friction Stir Process. The method, which will effectively and homogeneously spread the reinforcement within processed zone, will be considered as best possible method.Homogeneous volumetric metal matrix composites can be fabricated by conventional casting and modified stir casting methods. Friction stir process (FSP) can be used as one of the best technique to fabricate surface modified metal matrix composites. In this research article, silicon carbide and graphite powder are used as reinforced materials and AA6061 is used as parent metal matrix material. FSP which is a versatile surface composite preparation technique is applied for fabrication of surface composite. Herein, single channel, multi-channel and perforated holes methods have been utilized for reinforcement deposition. As per the results, perforated blind holes method is reported as best method of pre deposition of powders. Finally, array of holes for pre-deposition of reinforcement powder improves approx 25% in ultimate tensile strength , 40% in micro-hardness and appreciable grain refinement are observed in metal matrix composite processed by FSP as compared to as received alloy.

Microstructural and Mechanical Properties of AZ31B/Graphene Nanocomposite Produced by Stir Casting

In the current scenario, the development of high strength and low weight material is the demand of the aerospace defence organizations. Magnesium alloy based composite has low density, good mechanical and physical properties. In this study, magnesium alloy AZ31B is used as reinforcement material and graphene nanoparticle is used as reinforcement material. Stir casting technique is used for the development of composite material. Three weight percentages i.e. 0.4%, 0.8% and 1.2% are used for the casting. The microstructural analysis is performed to validate the presence of graphene particles in the developed composite. Further mechanical properties such as tensile strength, hardness and toughness are evaluated. Experimental results confirm that GNPs particles are uniformly distributed into the matrix material. It was observed that due to the reinforcement of GNPs particles tensile strength of the material is improved by 31.17%, hardness is improved about 46.9%. However, the peak value of toughness is observed 12.6 Jule/cm2 in the matrix material, it decreases by increasing the wt% of reinforcement particle and lowest value of toughness of 6.82 Jule/cm2 is observed in AZ31B/1.2%GNP composite.

Morphological and Mechanical Characterization of Al-4032/SiC/GMP Hybrid Composites

The pattern of metal matrix composites can be enhanced by integrating the concept of hybrid composite to produce newer engineering materials. The morphological and mechanical characteristics of Al-4032/SiC/GMP hybrid composites have been investigated. The aluminium alloy (Al-4032) based hybrid composites have been fabricated through the bottom pouring stir casting set up, by reinforcing the silicon carbide (SiC) and granite marble powder ceramic particles as the reinforcement material at various fraction level i.e. 0, 3, 6, 9 weight% in equal proportion. The reinforcement particle size is up to 54 µm. The microstructural characterization of the hybrid composite samples has been carried out using optical microscope, SEM and XRD. The study reveals that the reinforcement hybrid particles (SiC + GMP) are almost uniformly distributed throughout the matrix phase. The mechanical properties (tensile strength, impact strength and microhardness) of the composite samples have been obtained and found to be better than the unreinforced alloy.

A review on fabrication and characteristics of functionally graded aluminum matrix composites fabricated by centrifugal casting method

This paper delivers a detailed review of the influence of material and process variables on the microstructure, mechanical and tribological characteristics of functionally graded aluminum matrix composites (FGAMCs) produced by the ex-situ centrifugal casting method from previous studies. Also, the basic principle and classification of centrifugal casting to produce FGAMCs are illustrated. The ceramic reinforcement particles are classified based upon their uses in the processing of FGAMCs through the ex-situ centrifugal casting technique. In addition, using the linear regression model, an effort has been made to optimize the material and process variables to get enhance the mechanical properties. It is seen from the optimization while mold preheating temperature ranges 250–350 °C, centrifugal speed kept between 600 and 1300 rpm, pouring temperature in the range of 740–760 °C having reinforcement particle of 10–15 wt%, with an average particle size of 18–50 µm yield the maximum of hardness and tensile strength. This paper aims to provide direction to future researchers to develop advanced material using this route and thus, to boost technological growth.

The key attributes of processing parameters on semi-solid metal casting: An Overview

Commercialization of the developed technology is a prime factor for any nation and sector to retain its existence in this global economy. Day by day the technological advancement touching new high in various sectors like the automobile and aircraft industries but high design efficiency is achieved only when it is complemented by appropriate material. In the list newer addition is MMCs (Metal Matrix Composites) which are favorable because of their lower cost achieved by cheaper reinforcement, easy processing, and capabilities of mass production. In recent days, the importance of semi-solid casting has been well accepted among various processing routes for aluminum alloys despite many challenges in terms of process parameters like porosity, agglomeration, non-uniform reinforcement particle distribution, low wettability, and engulfment, and this is a main consideration for the present work. Semi-solid casting is considered to be one of the most important and effective manufacturing processes of aluminum alloy for viable mechanical and metallurgical properties in the current perspective of product requirement and competitiveness. A glimpse of the current status is presented, which shows the potential of the process which can be utilized by the industries for several benefits. In a nutshell, it can be found that process has the capability of alteration by the use of different scraps and also have flexibility according to the processing parameters like stirring, pouring temperature, type of reinforcements, etc.