Narrow Results

In this research work, aluminum 6063 alloy foam was synthesized through stir casting using varying amounts of titanium hydride as a foaming agent. A comparative microstructural and wear behavior analysis of stir-cast aluminum 6063 alloy and its foam is presented. The oxide and aluminide phases present as intermetallic compounds in the stir-cast aluminum 6063 alloy foam ensure the stability of the synthesized foam. In order to optimize the effect of wear parameters on the tribological properties of stir-cast aluminum 6063 alloy foam, the L₉3³ orthogonal array (OA) was designed and modeled statistically. The tribological properties of stir-cast aluminum 6063 alloy and its foam were evaluated by pin-on-disc tests. The optimal tribological properties of the synthesized foam are 0.29 coefficient of friction, 8.6 N frictional force, and 0.00025 mm³/N-m specific wear rate. The tribological properties of stir-cast aluminum 6063 alloy foam are superior to those of aluminum 6063 alloy and comparable to other aluminum foams described in the literature.

The development of lightweight and high-strength materials is critical for many industries, including aerospace, automotive, and electronics. Metal matrix composites (MMCs) have shown great promise in meeting these requirements. The structural and physical properties of Al6061 alloy reinforced with hybrid MMCs, including TiB2, SiC, and fly ash (FA), were investigated in this research review. The MMCs investigated were made using the stir-casting process. Their microstructure, structural characteristics, and mechanical features were examined. The inclusion of TiB₂ and SiC enhanced the composite’s hardness, tensile strength, and wear resistance, while the addition of FA lowered its density and improved its thermal and corrosion resistance. However, the volume percentage, particle dimension, and arrangement of the reinforcing components all had an effect on the physical characteristics of the composite. Therefore, the optimum combination of the reinforcing materials must be carefully selected to achieve the desired properties. The result of this review provides valuable insights into the development of high-performance MMCs for various industrial applications.

In this research, stir casting was used to create the aluminium alloy (AA7075) composite filled with 10wt.% zirconia (ZrO₂) particles as reinforcement. Die sinking electric discharge machining (EDM) was used to examine the machining characteristics of the proposed composite. The machining experiments were executed in accordance with the $L_9$ orthogonal layout. Here, the material removal rate (MRR) and surface roughness (SR) were taken into account as the output responses, and the discharge current ($I_p$), pulse on-time ($T_{\mathrm{\text{on}}}$), and pulse off-time ($T_{\mathrm{\text{off}}}$) were taken as the machining parameters. To determine the optimal parameter conditions for the output responses, the technique for order preference by similarity to ideal solution (TOPSIS) approach was applied. According to the experimental findings, the optimum settings of the parameters are determined at 15amps of ‘$I_p$’, 750$\mu$s of ‘$T_{\mathrm{\text{on}}}$’ and 50$\mu$s of ‘$T_{\mathrm{\text{off}}}$’. ANOVA results stated that ‘$T_{\mathrm{\text{on}}}$’ has the most notable factor with a contribution of 90.85%. The interaction effect of parameters on the responses was shown by the contour plots. The confirmatory experiment was finally conducted at the optimum machining parameter settings, and it was found that the error only occurred in 8.4%.

High strength and low weight materials are highly demanded in today’s automotive, aerospace, marine, medical, military, and agricultural equipment applications. Using composite materials is the best approach to increase high-strength and low-weight materials. This study focuses on evaluating the density, micro hardness, tensile, and wear behaviors of C355 aluminum alloy hybrid nanocomposites added in nanosized Graphene Oxide (GO) and Bio Silica (BS). These reinforcements are sourced from waste materials such as Thunder Coconut Shell (TCS) and Napier Grass (NG). The three different C355 aluminum alloy composites that have been improved by graphene oxide and bio-silica nanoparticles have been made utilizing the very traditional stir casting process. The percentage of GO and BS nanosized reinforcements is varied from 3wt.%, and 6wt.%. The cast composites density, hardness, and tensile strength are assessed. Unidirectional friction and wear tests are performed for each composition under six different loading conditions, ranging up to 60N, while maintaining a sliding speed of 5m/s. The worn surfaces and composite components underwent additional scrutiny through SEM analysis. By adding 6wt.% more GO/BS nanoreinforcement to the C355 Al alloy nanocomposite, the study’s findings show that the nanocomposite has almost 52.42% more tensile strength and 27.26% higher hardness than the basic alloy.

In this research, we added crushed rock sand (CRS) particles to an Al7075 matrix material, and composites were fabricated through a stir-casting approach. The reinforcement percentage varies from 0% to 12% by weight in discrete increments of 3%. Physical and mechanical parameters such as hardness, ultimate tensile strength, and impact toughness and corrosion performance by the gravimetric method, as well as tribological properties such as specific wear rate and coefficient of friction (COF), were tested at both ambient temperature ($30^{\circ }$C) and elevated temperature ($300^{\circ }$C). The density of the developed composite samples has been substantially lowered with an intensification in wt.% of CRS particles. The mechanical parameters of the developed composite samples have been considerably enhanced with an intensification in wt.% of CRS particles. The 9wt.% CRS-reinforced samples have an outstanding incrementation percentage of 52.44% hardness, 24.85% tensile strength, and 19.90% impact toughness. Better corrosion resistance is observed for the 9wt.% sample. Similarly, the same sample shows a 28.06% increase in specific wear rate at $30^{\circ }$C and a 43.35% increase at $300^{\circ }$C.

This work investigates the development and tribological performance of aluminum (Al) matrix composites reinforced with boron carbide (B₄C) particles at 2, 4, and 6wt.%. These composites were fabricated using a novel ultrasonic-assisted stir-casting approach. The inclusion of B₄C, a ceramic material known for its hardness and thermal stability, aimed to enhance the wear resistance of the Al matrix. Ultrasonic-assisted stirring ensured uniform dispersion of B₄C particles and reduced agglomeration, addressing a common issue in composite production. The developed composites with varying B₄Cwt.% were subjected to dry sliding wear testing using a pin-on-disc device and a Box-Behnken design of response surface methodology, incorporating variables such as load, sliding distance, and reinforcement wt.%. XRD analysis confirmed the presence of B₄C in the Al–B₄C composite. A slight peak shift was observed as the weight percentage of B₄C increased. The 2% Al–B₄C composite exhibited a 29% decrease in porosity compared to cast Al 6061. The inclusion of 2wt.% B₄C resulted in a significant 33% improvement in the composite’s hardness, reaching 86.6HV. Severe plastic flow and subsequent strain hardening were responsible for this increase in hardness. The ANOVA results primarily influenced the wear rate, with sliding distance and reinforcement weight percentage following closely behind. This study highlights the potential of Al–B₄C composites in applications requiring exceptional wear performance, such as the automotive and aerospace industries.

Aluminum metal matrix composites (AMMCs) are currently widely engaged in industrial sectors. No other monolithic material can match the characteristics of AMMCs. AMMCs are stronger than traditional materials and have a wide range of industrial uses. This research work aims to study the tribological properties of AA8079/Zirconium boride (ZrB₂) composite manufactured via the stir casting (SC) process. The different combinations of composites are AA8079/0wt.% ZrB₂, AA8079/5wt.% ZrB₂, AA8079/10wt.% ZrB₂, and AA8079/15wt.% ZrB₂. The parameters are reinforcement wt.% [A], load [B], sliding velocity [C], and sliding distance [D]. When designing experiments using the Taguchi method, an L${}_{16}$ orthogonal array was used. In order to determine which process parameter had the biggest influence on the output variables, wear rate (WR), coefficient of friction (COF), and analysis of variance (ANOVA) were applied. Successful fabrication of different weight fractions of ZrB₂ was synthesized with AA8079 matrix through the SC process. The microstructural investigations revealed the dispersion of ZrB₂ particles over the surface of the base AA8079. The response table clearly depicts that the combinations of A and C are the more dominant factor for WR, while the combinations of B and C are the more interacting parameters for COF. From the ANOVA results, it is clear that A with a 55.26% contribution, is the most predominant parameter in attaining the least WR, and for COF, B with a 31.39% contribution, is the major influencing parameter.

In this study, we optimize the wire electro-discharge machining (WEDM) parameters in zirconia (${\text{ZrO}}_2)$ ceramic particulates-filled Al7075 alloy composite by using the Taguchi-combined Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The Al7075 alloy composite was synthesized via the stir casting route by the addition of 10wt.% of ZrO₂ particulates. Scanning electron microscopy (SEM) was used to analyze the microstructure of fabricated composite. Experimental work was executed as per the $L_9$($3^3)$ orthogonal array design by considering three input machining parameters like pulse current ($I_p)$, pulse on-time ($T_{\mathrm{\text{on}}})$ and pulse off-time ($T_{\mathrm{\text{off}}})$, respectively. The material removal rate (MRR) and surface roughness (SR) were chosen as the output responses for machining of the developed composite. The signal-to-noise (S/N) ratio was employed to determine the optimum levels of machining parameters for the output responses. Moreover, analysis of variance (ANOVA) was used to find the significant contribution of parameters. The main effect plot explored that $I_p$ of 25 A, $T_{\mathrm{\text{on}}}$ of 115$\mu$s and $T_{\mathrm{\text{off}}}$ of 60$\mu$s were identified as the optimum levels of machining parameters which provide the maximum MRR (0.36757g/min) and minimum SR (3.826$\mu$m) for the proposed composite during the WEDM process. ANOVA results revealed that $I_p$ was the most dominant factor regarding MRR and SR followed by $T_{\mathrm{\text{on}}}$ with contributions of 74.05% and 14.48%, respectively.

In this study, Al/Al₂O₃ composites have been fabricated by combined stir casting and accumulative press bonding (APB) processes. The effect of APB method on the bonding properties of bulk samples such as the number of APB process, Al₂O₃wt.% and the pressing temperature has been investigated by the peeling test. It is established that stronger bonding with a good quality can be obtained by increasing the pressing temperature and decreasing the Al₂O₃ particleswt.% as the reinforcement. Also, growing the step number of the APB method increases the bonding strength up to step#2 and then reduces the average peeling force due to the strain hardening result of the metallic matrix during the accumulative pressing. Finally, the effect of the APB method on the peeling surface of samples has been investigated using the scanning electron microscopy.

This research focuses on the fabrication of Al6061/B₄C/Gr metal matrix composites as well as the mechanical and wear properties analysis. A liquid metallurgy stir casting process was used to cast the Al6061 alloy matrix composites with specific wt.% of B₄C and constant wt.% of graphite. In this work, newly developed composites of Gr (particle grain size: 0–20$\mu$m) and B₄C (particle grain size: 0–30$\mu$m) are reinforced with Al6061 pure alloy, which enhanced the mechanical and wear properties when compared to Al6061 pure alloy. Microstructure analysis was carried out concerning the developed mechanical properties. Furthermore, the dry sliding wear behavior of Al6061/B₄C/Gr metal matrix composites was investigated at a sliding speed of 1m/s and a sliding distance of 1500mm against a hardened EN-31 disc under the corresponding load of 19.68N. The minimum wear rate is $1.15\times 10^{-2}$mm³/m found at 15wt.% B₄C and 2wt.% graphite and the coefficient of friction is 0.54 that decreases with graphite addition, with the lowest value obtained with 5wt.% B₄C and 2wt.% graphite. Al6061/10wt.% B₄C/2wt.% Gr particles-reinforced composite material demonstrated the highest tensile and flexural strengths. The hardness,compressive and tensile strength of the Al6061/15wt.% B₄C/2wt.% Gr particles-reinforced composite material were the highest. Scanning electron microscopy was used to examine the worn surfaces of wear specimens. The main objective of this work is to develop hybrid Al6061/B₄C/Gr composites with improved mechanical and wear properties when compared with the base alloy. Al6061 is widely used in automobiles parts like engine block, piston rings, alloy wheels, marine industries, etc. B₄C used in the composite improves strength and is used commonly in armed bullet proof. The Gr present in the composite improves wear resistance, and therefore applied in wear-resistant parts like brake, piston with cylinder, etc.

In the current scenario, many researchers aspire to develop biodegradable material for biomedical implant applications. Magnesium (Mg)-based alloys are most promising materials since they have mechanical properties similar to human bone. In this study, Mg alloy AZ31 matrix was reinforced with a seashell powder (2wt.%) and zirconium dioxide (10wt.%) using bottom pouring stir casting furnace. Scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) images confirms the proper distribution of reinforcement throughout the matrix. This study analyzed the influence of WEDM process parameters for the material removal rate (MRR) and surface roughness (SR) of the proposed composite. According to Taguchi’s L₉ (3${}^3)$ orthogonal array the machining was performed to investigate the ideal machining parameters with a range of pulse current (I${}_p)$ 6–8 amps, pulse-on time ($T_{\mathrm{\text{on}}}$) 5–15$\mu$s and pulse-off time ($T_{\mathrm{\text{off}}})$ 10–30$\mu$s, respectively. Analysis of variance (ANOVA) result confirms that $I_p$ (45.86%) has the most influencing parameter affecting the MRR and SR, followed by $T_{\mathrm{\text{on}}}$ (25.10%) and $T_{\mathrm{\text{off}}}$ (17.19%), respectively. Furthermore, Technique for Order Preference by Similar Ideal Solution (TOPSIS) and desirability approach was employed to find the optimal parameter combinations to attain the best combined output responses.

Wire cut electric discharge machining (WCEDM) is a flexible and more essential for the precise machining of hard materials like composites and super alloys. In order to improve the surface texture as the main focus of the WCEDM process, the expansion of the fundamental procedural perceptive is very important. This paper mainly focuses on the prediction of surface quality of Al-Fe-Si alloy (AA8011) matrix composites during the WCEDM process. For the fabrication of composites, the varying proportions (0, 5, 10 and 15 wt.%) of ZrO₂ ceramic particle were incorporated with AA8011 matrix alloy by using stir casting method. In the machining studies, to investigate the effects of reinforcement (wt. %) and the WCEDM process parameters, namely pulse current (amps), pulse-on time ($\mu$s) and pulse-off time ($\mu$s) on machining performance like surface roughness (SR) of the proposed composites. Based on the selection of parameters and their levels, an L16 (4⁴) orthogonal array was most suitable for conducting the WCEDM experiments. A Taguchi technique was employed in this study to determine the optimal conditions of machining parameters through the signal-to-noise (S/N) ratio analysis. The result shows that the minimum SR is achieved at 5 wt.% of reinforcement, 6 amps of pulse current, 110 $\mu$s of pulse-on time and 50 $\mu$s of pulse-off time, respectively. Analysis of variance (ANOVA) results revealed that the reinforcement wt.% has the primary significant factor on SR, trailed by pulse-on time and pulse current, respectively. Furthermore, the regression equation was also developed to predict the SR and that values well agree with the experimental SR.

Al7075 is employed as the matrix material and sugarcane bagasse ash (SBA) is a reinforcing material in this work, which is targeted at creating lightweight metal matrix composites (MMCs) at a reasonable cost. Hybridized improved composite castings have been produced and industrial as per ASTM standards with changing wt.% of 0%, 4%, 8%, 12%, and 16% wt.%, correspondingly, after mechanical testing for the evaluation of their strength. It is tested for hardness, tensile, impact, and flexural strength. Composites with hybrid enhanced metal matrix have greater tensile, hardness, and flexural strengths than single-reinforced MMCs. The composite’s tensile and flexural strengths were boosted by a 12wt.% increase in bagasse ash, which resulted in maximum values of 96.42% tensile and 23.58% flexural strength, respectively. As the bagasse weight percentage grew over 12%, these values fell, although Bagasse ash AA7075’s impact and ductility improved slightly.

This work aims to develop a mathematical model and predict the machining performance characteristics of electric discharge machining (EDM) process using response surface methodology (RSM) coupled with desirability function approach (DFA). The effect of various factors, such as electrode material, pulse current, pulse ON time and pulse OFF time were selected as input process parameters with an objective to maximize the material removal rate (MRR), minimize the surface roughness (SR) and electrode wear ratio (EWR). The machining was conducted on Al-Zn-Mg-Cu (AA7075) alloy composite reinforced with 10wt.% TiO₂ particulates produced by stir casting route. The experimental work was planned as per L27 orthogonal array using design of experiments through RSM. Experimental results show that, pulse current and pulse ON time are the most significant factors for MRR and SR while electrode materials and pulse current have notable effect on EWR. Finally, multi-response optimization was performed to predict the EDM parameters by using DFA. The optimum combination of parameters were identified as electrode material (Br), pulse current (15 amps), pulse ON time (900$\mu$s) and pulse OFF time (30$\mu$s).

This paper reports deformation mechanism studies by varying height-to-diameter ratio of aluminum (Al), aluminum–magnesium (Al–Mg) and aluminum–magnesium–carbon (Al–Mg–C) metal matrix composites prepared using stir casting technique. Specimen were machined to the required sizes, having different $h∕d$ ratios (i.e. $(h∕d)<1$, $=1$ and $>1$). Mechanical properties such as hardness and deformation of the undeformed and deformed specimens were examined. Deformation test was performed under a load of 14 tonnes at different interfacial frictional conditions, i.e. dry, solid lubrication and liquid lubrication. The study revealed significant improvement in densification and hardness behavior in the composites as compared to its base metals and alloys.