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The term “smart materials” can be used to refer a wide variety of different kinds of substances. One capacity that is shared by all of them is the capability to radically alter one or more aspects while operating inside carefully controlled conditions. The age of intelligent materials is arrived, and we are living in it right now. An older definition of smart material described it as a substance that responds swiftly to the environment in which it is located. It has been argued that the word “smart material” now refers to any substance that is capable of detecting, transmitting, or processing a stimulus in order to produce a beneficial effect. This idea has been put forward as a possible expansion of the original meaning of the term. The purpose of this research is to define and categorize different types of intelligent materials. Uses of smart materials are being contemplated in a wide variety of domains, spanning from the realm of technology to that of the modern environment.

The nickel-based Colmonoy-5 hardfacing alloy is used to hard-face 316LN austenitic stainless steel components in fast reactors. The nominal composition (in wt%) was listed as follows: 0.01 C, 0.49 Si, 0.87 Mn, 17.09 Cr, 14.04 Ni, 2.56 Mo, 0.14 N, and balance Fe. Hardfacing is a technique of applying hard and wear-resistant materials to substrates that need abrasion resistance. The thickness of hardfacing deposit varies between 0.8 mm and 2 mm based on parameter combinations. In this study, laser hardfacing process parameters including laser power, powder feed rate, travel speed, and defocusing distance were optimized to reduce weight loss of laser hard-faced Ni-based deposit. The tribological characteristics of reactor-grade NiCr-B hard-faced deposits were investigated. The RSM technique was used to identify the most important control variables resulting in the least weight loss of the nickel-based alloy placed on AISI 316LN austenitic stainless steel. Statistical techniques like DoE and ANOVA are utilized. Changing the laser settings may efficiently track the weight loss of laser hard-faced nickel alloy surfaces. These are created using the response surface technique. The deposit produced with a laser power of 1314 W, powder feed rate of 9 g/min, travel speed of 366 mm/min, and defocusing distance of 32 mm had the lowest weight loss of 16.4 mg. Based on the F value, the powder feed rate is the major influencing factor to predict the hardness followed by power, travel speed, and defocusing distance.

Copper-coated steel wires (5 numbers) were uniformly reinforced in AA336 aluminium alloy using squeeze casting process. Microstructure of castings was examined, and dry sliding wear test was performed by considering the factors viz., load (10–50 N), velocity (1–5 m/s) and sliding distance (500–2500 m). Response surface methodology was used to design the experiments by considering three factors, five levels central composite design. A regression model was developed to predict the weight loss of composites and checked its adequacy using significance tests, analysis of variance and confirmation tests. Worn surfaces of composite were investigated using field emission scanning electron microscope and reported with wear mechanisms. Dry sliding wear parameters were optimised for obtaining minimum weight loss. Microstructure of casting showed the reinforcement of steel wires in AA336 aluminium alloy and copper coating on steel wires offered better interface bonding between matrix and reinforcement. Response surface plots revealed that weight loss of composites increased with increasing load and sliding distance. Worn surface of composites showed fine grooves at lower loads and delamination was observed at higher loads. 18.1 N load, 2.41 m/s velocity and 2094 m sliding distance were observed as optimum dry sliding wear parameters for obtaining minimum weight loss.

Copper coated steel fibers reinforced LM13 aluminium alloy composites have been prepared using stir casting process. Experiments have been designed using response surface methodology by varying wt% of reinforcement (0–10), stirrer speed (350–800 rpm) and pouring temperature (700–800 °C). Microstructure, tensile strength and fracture surface of composites have been investigated. Analysis of variance, significance test and confirmation tests have been performed and regressions models have been developed to predict the tensile strength of composites. Response surface plots reveal that tensile strength of composites increases with increasing wt% of copper coated steel fibers reinforcement up to 6 wt%. Further increase in wt% of steel fibers decreases the tensile strength of composites. However tensile strength of composites increases with increasing stirrer speed due to the uniform and homogeneous dispersion of steel fibers in matrix. Optimum stir cast process parameters for obtaining higher tensile strength are found to be 5.9 wt% of reinforcement, 753 °C pouring temperature and stirrer speed of 633 rpm. Fracture mechanism is dominated by steel fiber pullouts in composites with higher wt% of reinforcement and dimples are observed in the surface of composites containing lower levels of wt% of reinforcement.

Copper coated steel wires (1–5 numbers) reinforced in LM13 aluminium alloy composites have been prepared using squeeze casting process. Microstructure of composites has been investigated and mechanical properties viz., hardness, tensile strength and ductility have been examined and reported. Dry sliding wear behaviour of composites has been investigated by varying sliding distance and load. Fracture surface of broken tensile specimens and worn surface of wear samples have been investigated using field emission scanning electron microscope (FESEM). The results reveal that copper coated steel wires reinforcement in LM13 aluminium alloy improves the mechanical properties and wear resistance. Average hardness values of 136 BHN and 96 BHN have been observed in steel wire and at the interface of steel wire and aluminium alloy, respectively. Tensile strength of composites increased up to 28% by reinforcing three copper coated steel wires in LM13 aluminium alloy. Dry sliding wear test results reveal that weight loss, wear rate and coefficient of friction decreased with increasing number of copper coated steel wires reinforcement in LM13 matrix. However, weight loss of samples increased with increasing sliding distance and load. LM13 aluminium alloy reinforced with five numbers of copper coated steel wires decreased the weight loss up to 69% as compared to LM13 aluminium alloy tested at 40 N load and a sliding distance of 2500 m. Fracture surface of composites shows broken steel wires and dimples are observed in LM13 matrix. Worn surface of composites shows fine and shallow grooves; whereas delamination is observed in LM13 aluminium alloy. In general, copper coated steel wire reinforcement in LM13 aluminium alloy exhibited better mechanical properties and wear resistance compared to matrix.

LM6 aluminium alloy with 2.5–10 wt% of copper coated short steel fiber reinforced composites were prepared using squeeze casting process. Microstructure and mechanical properties viz., hardness, tensile strength and ductility were investigated. Dry sliding wear behaviour was tested by considering sliding distance and load. Fracture surface and worn surface were examined using field emission scanning electron microscope (FESEM). Hardness of composites increased with increasing wt% of fiber. Tensile strength of composites increased up to 19% for 5 wt% fiber composites. Further addition of fibers decreased the tensile strength of composites. Ductility of the composites decreased with the addition of fibers into the matrix. Wt% of fibers significantly decreased the weight loss, coefficient of friction and wear rate. Also the cumulative weight loss decreased up to 57% for 10 wt% of composites compared to LM6 aluminium alloy. Fracture surface of composite tensile specimen showed dimple formation and fiber pullout. Worn surface of matrix showed long continuous grooves due to local delamination on the surface. However, worn surface of composites showed fine and smooth grooves due to ploughing rather than local delamination. Copper coated steel fiber reinforcement in LM6 aluminium alloy exhibited better mechanical properties and wear resistance compared to matrix.

Uncoated and copper coated steel wire mesh reinforcing LM6 aluminium alloy composites have been produced using squeeze casting process by varying reinforcement orientation viz., 0°, 45° and 90° respectively. Microstructure of the castings has been examined and mechanical properties such as hardness, tensile strength and ductility have been investigated. Fracture surface of tensile specimens has been analysed using field emission scanning electron microscope. Microstructure of samples reveals that copper coating on steel wires improves the interface bonding between matrix and reinforcement. Average hardness values of 259 and 90 Hv have been observed in steel wire and matrix respectively. Tensile strength of composites increases with increasing angle of reinforcement orientation from 0° to 90°. Tensile strength increases up to 11% by reinforcing copper coated steel wire mesh at 90° orientation as compared to LM6 aluminium alloy. Fracture surface of composites shows pullout of steel wires in uncoated steel wire mesh composites and broken wires in copper coated steel wire mesh composites respectively. Dimples have been observed on the fracture surface of LM6 aluminium alloy. In general, copper coated steel wire mesh composites offer better hardness and tensile strength compared to uncoated steel wire mesh composites and LM6 aluminium alloy. This may be attributed to the copper coating on steel wires which results better interface bonding between matrix and reinforcement.

Dry sliding wear is one of the predominant factors to be considered while selecting material for automotive and aerospace applications. Researchers have been exploring novel aluminium matrix composites (AMC), which offer minimum wear rate for various tribological applications. In this present work, an attempt has been made to reinforce LM13 aluminium alloy with copper coated steel fibers (10wt.%) using squeeze casting process and to perform dry sliding wear test using pin-on-disc tribometer. Microstructure of cast samples was examined using image analysis system to investigate the dispersion of reinforcement in matrix. Dry sliding wear test was performed by considering factors such as load (10-50 N), sliding velocity (1-5 m∙s-1) and sliding distance (500-2,500 m). Wear test was performed according to the experimental design at room temperature. Three factors and five levels central composite design were used to design the experiments using response surface methodology. Based on the results of the experiments, a regression model was developed to predict the wear rate of composites and checked for its adequacy using significance tests, analyses of variance and confirmation tests. Worn surface of samples was investigated using field emission scanning electron microscope and reported with its mechanisms. Microstructure of cast samples revealed uniform dispersion of reinforcement throughout the matrix. Response surface plots revealed that wear rate of composites increases with increasing load up to 50 N with the velocity 1-5 m∙s-1 and a sliding distance up to 2,500 m. However wear rate decreasesd with increasing velocity at lower loads (up to 20 N) and increased after reaching transition velocity of 2 m∙s-1. Dry sliding wear process parameters were optimised for obtaining minimum wear rate and they were found to be a load of 18.46 N, velocity of 4.11 m∙s-1, sliding distance of 923 m. Worn surface of samples revealed a mild wear at lower loads (up to 30 N), and severe wear was observed at high loads (40-50 N) due to higher level of deformation on the surface.

Zinc-coated steel wires (1–5 numbers) reinforced in LM6 matrix composites have been prepared by squeeze casting process. Microstructure, hardness, tensile strength, ductility and dry sliding wear behavior of composites have been investigated by varying sliding distance and load. Fracture surface of tensile specimens and worn out surface of wear samples have been examined using field emission scanning electron microscope (FESEM). The results reveal that hardness of composites increased with increasing distance from matrix to steel wires. Maximum hardness values of 751 VHN and 611 VHN are observed in steel wire and at the interface of steel wire — aluminium, respectively. Tensile strength of composites increased upto 24% by reinforcing three steel wires in matrix. During the wear test, weight loss, wear rate and coefficient of friction decreased with increasing number of wires embedded in matrix and increased with increasing sliding distance and load. LM6 aluminium alloy reinforced with five numbers of steel wires decreased the weight loss upto 17% as compared to matrix under 40[Formula: see text]N load and a sliding distance of 2000[Formula: see text]m. Fracture surface of tensile specimen shows dimple formation in matrix and broken wires are observed in composites. Worn surface of composites shows fine grooves, whereas delamination is observed in matrix. In general, reinforcement of zinc-coated steel wires in LM6 aluminium alloy exhibited better mechanical properties and wear resistance compared to matrix.

Copper coated steel fibers reinforced LM13 aluminium alloy composites have been prepared using stir casting process. Experiments have been designed using response surface methodology (RSM) by varying wt% of reinforcement (0–10), pouring temperature (700–800 °C) and stirrer speed (350–800 rpm). Microstructures and dry sliding behaviour of composites have been investigated and reported. Composites prepared using high stirring speed shows uniform dispersion of reinforcement throughout the matrix. Regression equation is developed to predict the weight loss of composites and the error percentage is ±7. Response surface plots reveal that weight loss of composites decreased with increasing wt% of reinforcement and stirrer speed. Stir cast process parameters have been optimised for obtaining minimum weight loss and it's found to be a wt% of reinforcement of 8.17, pouring temperature of 778 °C and stirrer speed of 658 rpm. Worn surface shows fine grooves and shallow grooves in composites with higher wt% of reinforcement and delamination is observed for the composite contains lower wt% of reinforcement.