Al-TiB2 Metal Matrix Composite Research Articles

Machining quality comparison of Al-TiB2 composite using conventional EDM and magnetic force-assisted powder-mixed EDM

ABSTRACT Now a day’s researchers are working hard to improve the process performance of unconventional or advanced machining processes by hybridising them with other mechanisms. In the present research, a hybrid variant of electrical discharge machining (EDM) has been proposed by developing a setup to create a rotating magnetic field near the machining zone and also by mixing a conductive powder (chromium, 325 mesh size) on a separate dielectric tank. The machining performance of indigenously developed hybrid magnetic force assisted powder mixed electric discharge machining (MFPEDM) has been compared with conventional EDM during machining of Al-TiB2 metal matrix composite. The comparison results elucidate considerable improvements in material removal rate (39.27%), surface finish (54.45%), and overcut (44.97%) by MFPEDM as compared to EDM.

Multicriteria Selection of Friction Stir Welded Al-Tib2 Metal Matrix Composites using WASPAS to Improve Composite Development and Design

The unique area of friction stir welding that involves Al-TiB2 composite development stirs controversy and fails to offer a clear understanding of how to choose the best composite among alternatives without subjectivity. At present, the experienced fabricator uses intuition in judgement, leading to wrong or inconsistent decisions. In this paper, the WASPAS multicriteria model is deployed to choose the best Al-TiB2 composite among options using tensile strength, ductility and microhardness as attributes. The procedure generally entails normalization, preference score and ranking determination and literature data was used. The emerging conclusion from this study is that irrespective of the weight determination method and the multicriteria model adopted to evaluate the alternative fabricated Al-TiB2 composites, the Al-10%TiB2 and Al6065 based alloy always reveal as the best and worst composites, respectively, even under varied normalisation methods. The research confirmed that multicriteria analysis is a potential objective method to choose among fabricated alternatives. The work showed that there is scope to evade the consequences of subjectivity in composite decision making by attaching adequate weights to the deciding factors thereby avoiding misguidance and incorrect decision making. Furthermore, multicriteria models offer novel approaches to understand the relative preference of fabricating composites to one another in the metal matrix composite development area.

Corrosion behavior of stir-cast Al–TiB2 metal matrix composites

Abstract The present study evaluates the corrosion behavior of Al–TiB2 metal matrix composites in 3.5% NaCl solution. Composites are fabricated using stir-casting with varying wt.% of TiB2. Composite surfaces are characterized using scanning electron microscopy (SEM) images. Micro-hardness values of composites are obtained using a Vicker's micro-hardness tester. The hardness of the base matrix is enhanced due to the incorporation of hard TiB2 phase. Corrosion characteristics of composites are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Corrosion resistance of composites is estimated from the parameters such as corrosion potential, corrosion current, linear polarization resistance etc. Corrosion resistance of the base alloy improves due to incorporation of TiB2 but only up to a certain amount of TiB2 phase in the matrix. The composite with 1 wt.% TiB2 shows the highest corrosion resistance. Corroded surfaces are studied using SEM images that reveal localized pitting corrosion on composite surfaces.

Design of Experiments Analysis of Abrasive Wear Behavior of Stir Cast Al-TiB2 Composites

Abstract Present study deals with the abrasive wear behavior of Al-TiB2 metal matrix composites. Composites have been fabricated through stir-casting method containing three different weight percentages of reinforcement. Abrasive wear tests have been performed in pin-on disk tribometer carrying bonded abrasive silicon carbide papers of three different grades. Wear values are obtained in terms of weight loss after completion of the each test. Wear results are obtained according to the design of experiments based on Taguchi L27 orthogonal array. Weight percentage (wt %) of TiB2, load and grade of the abrasive papers have been chosen as design parameters. For each parameter, three different levels are used. Taguchi method is applied on the wear results to find out the optimal combination of parameters. Analysis of variance is performed to get the idea about contribution of each parameter and their interactions. Abrasive wear mostly depends on the abrasive particle size. With increase in the particle size, wear increases. As per ANOVA table, abrasive particle size holds 74.41% contribution in influencing wear behavior.

Tribological Characteristics of Stir-Cast Al-TiB2 Metal Matrix Composites in Lubricated Condition Using Taguchi Based Grey Relation Analysis

The present study considers an experimental study of tribological performance of Al-TiB2 metal matrix composite under lubricated condition and optimization of testing parameters viz. weight percentage of TiB2, load, and speed together based on Taguchi method coupled with grey relational analysis to minimize wear and friction characteristics. A grey relational grade obtained from grey relational analysis is u.sed as a performance index to study the behavior of Al-TiB2 composite in presence of SAE20W40 petroleum based lubricant with respect to friction and wear characteristics. L27 orthogonal array has been used to optimize parameters through Taguchi based grey relation analysis. Al-TiB2 metal matrix composite is developed through stir casting method by reinforcing TiB2 particulates into LM4 aluminum alloy. It is observed that weight percentage of TiB2 has a significant contribution in controlling the friction and wear behavior of Al-TiB2 metal matrix composite. Presence of lubricant shows the negation of effect of weight percentage of particulate in the interacting surface region. Load is the most influential factor as it determines the film thickness of the lubricant in a very definite way. In addition, scanning electron microscopy (SEM) is performed on the wear tracks to differentiate the wear mechanism between dry and lubricated condition

The preparation and mechanical properties of Al metal matrix composites by in-situ method

The aluminium-based composites are widely being used in the transport, aerospace, marine, automobile and mineral processing industries. Preparation of Al/TiB2 composites by in-situ processing offers significant advantages over the conventional processing from both technical and economic standpoints. The technique of salt-metal reactions is an attractive in-situ approach for preparing Al-TiB2 metal matrix composites. It involves in mixing of Ti and B bearing salts (i.e., K2TiF6 and KBF4) to molten aluminium, giving rise to the formation of dispersion of TiB2 particles in the aluminium matrix. The obtained as-cast metal matrix composite is carefully machined to prepare the test specimens for hardness, tensile as well as microstructure studies as per ASTM standards. The hardness, tensile strength and microstructure properties of Al6061-TiB2 composites are explored experimentally. Finally, the material characterisation of heat treated sample and as-cast samples are compared.

The preparation and mechanical properties of Al metal matrix composites by in-situ method

The aluminium-based composites are widely being used in the transport, aerospace, marine, automobile and mineral processing industries. Preparation of Al/TiB2 composites by in-situ processing offers significant advantages over the conventional processing from both technical and economic standpoints. The technique of salt-metal reactions is an attractive in-situ approach for preparing Al-TiB2 metal matrix composites. It involves in mixing of Ti and B bearing salts (i.e., K2TiF6 and KBF4) to molten aluminium, giving rise to the formation of dispersion of TiB2 particles in the aluminium matrix. The obtained as-cast metal matrix composite is carefully machined to prepare the test specimens for hardness, tensile as well as microstructure studies as per ASTM standards. The hardness, tensile strength and microstructure properties of Al6061-TiB2 composites are explored experimentally. Finally, the material characterisation of heat treated sample and as-cast samples are compared.

Studies on parametric optimization for abrasive water jet machining of Al7075-TiB2 in-situ composite

The study focuses on optimization and determination of significant process parameter for Abrasive Water Jet Machining of Al7075-TiB2metal matrix composite. Al-TiB2 metal matrix composite is synthesized by stir casting using in-situ technique. Optimization of machining parameters is done using Taguchi's L25orthogonal array for the experimental trials, with cutting speed, stand-off distance and Abrasive Flow rate as input parameters at five different levels. Analysis Of Variance (ANOVA) method is used for identifying the effect of machining parameters on volumetric material removal rate, surface roughness and dimensional accuracy. Then the results are validated by conducting verification experiments.

Wear performance optimization of stir cast Al-TiB2 metal matrix composites using Taguchi design of experiments

The present study outlines the use of Taguchi parameter design to minimize the wear performance of Al-TiB2 metal matrix composites by optimizing tribological process parameters. Different weight percentages of micro-TiB2 powders with average sizes of 5-40 micron are incorporated into molten LM4 aluminium matrix by stir casting method. The wear performance of Al-TiB2 composites is evaluated in a block-on-roller type Multitribo tester at room temperature. Three parameters viz. weight percentage of TiB2, load and speed are considered with three levels each at the time of experiment. A L27 orthogonal array is used to carry out experiments accommodating all the factors and their levels including their interaction effects. Optimal combination of parameters for wear performance is obtained by Taguchi analysis. Analysis of variance (ANOVA) is used to find out percentage contribution of each parameter and their interaction also on wear performance. Weight percentage of TiB2 is forced to be the most effective parameter in controlling wear behaviour of Al-TiB2 metal matrix composite.

Aluminium-Titanium Diboride (Al-TiB2) Metal Matrix Composites: Challenges and Opportunities

A review of Al based metal matrix composite reinforced with TiB2 particles developed after 1997 is presented in this paper. This paper presents an overview of Al-TiB2 MMC on aspects relating to the formation of TiB2, development of Al-TiB2, mechanical characteristics, thermodynamic calculation, wear behavior of Al-TiB2, cycle fatigue response of insitu Al based composite, processing, microstructure, properties and application are discussed. Aluminium alloys are widely used for commercial applications in the transportation, construction and similar engineering industries. Nowadays, main focus is given to Aluminium as matrix material because of its unique combination of good corrosion resistance, low electrical resistance and it possesses excellent mechanical properties in addition to good corrosion resistance due to which the alloy finds extensive application in naval vessels manufacturing. Al-TiB2 composite is a metal matrix composite (MMC) that can be manufactured using the in-situ salt-metal reaction. With TiB2 as the particulate addition the properties of Al 6061 alloy can be greatly improved. The addition of TiB2 to aluminium increases the strength of the aluminium. The wear resistance of this material is due to the lack of pull out of this material from the aluminium matix. Also, such material when machine with non–conventional methods like EDM will show better machinability due to its high conductivity. In the last few years, Al-TiB2 have been utilized in high-tech structural and functional applications including aerospace, defense, automotive, and thermal management areas, as well as in sports and recreation. The future research is summarized finally.

A Comparative Study on the Microstructures and Mechanical Properties of Al 6061 Alloy and the MMC Al 6061/TiB<sub>2</sub>/12<sub>p</sub>

Al 6061 alloy is widely used for commercial applications in the transportation, construction and similar engineering industries. It possesses excellent mechanical properties in addition to good corrosion resistance due to which the alloy finds extensive application in naval vessels manufacturing. Al-TiB2 composite is a metal matrix composite (MMC) that can be manufactured using the in-situ salt-metal reaction. With TiB2 as the particulate addition the properties of Al 6061 alloy can be greatly improved. A comparison of the mechanical properties and the microstructure of Al 6061 alloy with Al–TiB2 metal matrix composite containing 12% by weight TiB2p manufactured through the in-situ process was presented.

In situ preparation of TiB2 reinforced Al base composite

In situ formation of Al-TiB2 metal matrix composite has been successfully fabricated through an exothermic reaction process. The base alloy used in the present investigation was Al-4 wt% Cu. It was first melted at 850°C. After that, two types of salts, namely, K2TiF6 and KBF4 were added into the molten Al alloy by stirring. An exothermic reaction between the two salts and molten Al took place to form in situ TiB2 particulates in the molten Al alloy. The exothermic reaction period was varied from a minimum 5 min to a maximum 35 min to investigate the relationship between the degree of reaction, the growth behaviour and the microstructures of TiB2. After the reaction, the composite was cast into rods of 25 mm diameter. Both X-ray diffraction measurement and scanning electron microscope analysis revealed the formation of TiB2. The amount of TiB2 particulates increased when the exothermic reaction period was prolonged. Its microstructure was examined under optical and scanning electron microscopes.