Ankush Anand

Bio: Ankush Anand is an academic researcher from Shri Mata Vaishno Devi University. The author has contributed to research in topics: Tribology & Supply chain. The author has an hindex of 14, co-authored 46 publications receiving 631 citations.

Industrial applications of natural fibre-reinforced polymer composites – challenges and opportunities

Abstract: The growing industrial demand for sustainable materials has led to a paradigm shift in the focus from synthetic polymers towards natural fibres. This paper deals with the challenges and opportuniti...

Dry Sliding Friction and Wear Behavior of AA7075-Si 3 N 4 Composite

Abstract: The present investigation is aimed at identifying the influence of Si3N4 reinforcement on the mechanical and tribological behavior of AA7075-Si3N4 composite. Five different composites of AA7075 aluminum alloy reinforced by silicon nitride particles have been fabricated by the stir casting route. The percentage of silicon nitride was varied from 0-8 wt%. The cast composites were tested for hardness, density and compression strength. Unidirectional friction and wear testing was carried out for all compositions under five different loading conditions (10 N, 20 N, 30 N, 40 N and 50 N) at a constant sliding speed of 1 m/s. SEM and EDS analysis was also carried out for worn surface analysis and elemental analysis of the composites. The hardness and compression strength of the composites exhibited an increasing trend with an increase in wt% of reinforcement in the base alloy, showing 20% improvement in hardness and around 50% improvement in compression strength for 8 wt% Si3N4 addition. The addition of Si3N4 particles led to an improvement in the wear resistance by 37% at low loads (10 N) and 61% at higher loads (50 N). The COF for all varied compositions at low load (10 N) and high load (50 N) ranges from 0.10 to 0.20 and 0.25 to 0.30 respectively. Moreover, the COF is observed to increase until 4 wt% and beyond it decreases. Microscopic studies of worn surfaces revealed a dominance of delamination wear at lower concentrations (0 wt% and 2 wt%) and ploughing at higher concentrations (6 wt% and 8 wt%). The developed composites exhibited better mechanical and anti-wear properties and could serve as potential candidates in sliding applications such as bearings, brake drums, gears, sprockets and brake rotors.

Synthesis and tribological investigation of Al-SiC based nano hybrid composite

Abstract: In this study, a novel self lubricating nano-composite Al-SiC-nAl2O3-WS2 has been synthesized via powder metallurgy method. Nano-Al2O3 has been prepared via combustion synthesis. Three different compositions by varying the amount of solid lubricant, WS2 (0, 5, 9) wt.% were synthesized and analyzed. The density measurements of composites were carried out by using Archimedes Principle. The micro hardness value of every composition was obtained by using micro hardness tester. The tribological properties were investigated under dry and unidirectional sliding conditions on a pin on disk tribometer. Taguchi L9 orthogonal array was used to study the effects of various parameters like load, content, speed and sliding distance on wear and frictional behavior of the composites. Analysis of variance (ANOVA) was used to investigate the percentage contribution of various parameters on the wear and friction behavior. It was observed that composite with 5 wt.% of WS2 exhibited lower friction and wear. SEM images obtained therein revealed that ploughing and abrasion are the two dominant mechanisms of wear.

Tribological investigation of diamond nanoparticles for steel/steel contacts in boundary lubrication regime

Abstract: This paper presents an investigation of nanodiamond additives (ND) in combination with copper oxide (CuO) and hexagonal boron nitride (h-BN) particles mixed in PAO (poly-alpha-olefin) oil. The experimentation was performed for a ball on disc configuration using steel/steel contacts in the boundary lubrication regime. The loads were varied from 20 to 100 N and sliding velocity was kept constant at 0.58 m/s. The wear behavior was evaluated using SEM images of the worn-out disc surfaces. EDS analysis of the samples was performed to find out the chemical content of the worn surfaces. Results obtained therein demonstrated that oil containing CuO/ND and h-BN/ND exhibited better frictional and wear characteristics. For CuO/ND containing lubricant, the maximum decrease in friction coefficient is 15.45% in comparison to the CuO oil, whereas for h-BN/ND containing additives the overall decrease is 25.45%. It was observed that the combined effect of CuO/ND and h-BN/ND due to their intrinsic characteristics led to the overall improvement in lubrication properties of the base oil.

Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications.

Abstract: Composites have been found to be the most promising and discerning material available in this century. Presently, composites reinforced with fibers of synthetic or natural materials are gaining more importance as demands for lightweight materials with high strength for specific applications are growing in the market. Fiber-reinforced polymer composite offers not only high strength to weight ratio, but also reveals exceptional properties such as high durability; stiffness; damping property; flexural strength; and resistance to corrosion, wear, impact, and fire. These wide ranges of diverse features have led composite materials to find applications in mechanical, construction, aerospace, automobile, biomedical, marine, and many other manufacturing industries. Performance of composite materials predominantly depends on their constituent elements and manufacturing techniques, therefore, functional properties of various fibers available worldwide, their classifications, and the manufacturing techniques used to fabricate the composite materials need to be studied in order to figure out the optimized characteristic of the material for the desired application. An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications. Their exceptional performance in the numerous fields of applications have made fiber-reinforced composite materials a promising alternative over solitary metals or alloys.

A group decision making sustainable supplier selection approach using extended TOPSIS under interval-valued Pythagorean fuzzy environment

Abstract: Due to the increasing awareness of environmental and social issues, sustainable supplier selection becomes an important problem. The aim of this paper is to develop a novel group decision making sustainable supplier selection approach using extended Techniques for Order Preferences by Similarity to Ideal Solution (TOPSIS) under interval-valued Pythagorean fuzzy environment. Sustainable supplier selection often involves uncertain information due to the subjective nature of human judgments, and the interval-valued Pythagorean fuzzy set (IVPFS) has great ability to address strong fuzziness, ambiguity and inexactness during the decision-making process. The first contribution of this research is to use the IVPFS to capture the uncertain information of decision makers. Moreover, sustainable supplier selection often involves multiple decision makers from different groups. The second contribution of this research is to develop a group decision making approach for sustainable supplier selection. TOPSIS is the most commonly used technique in sustainable supplier selection. The third contribution of this research is to propose an extended TOPSIS method by integrating distance and similarity between alternatives concurrently to evaluate performances of suppliers. In this research, the group decision making approach and extended TOPSIS method is also extended to IVPFSs. Finally, experiments are conducted to verify the feasibility and efficiency of the proposed sustainable supplier selection approach. Experiments results show that the proposed approach is effective and efficient to help decision makers to select optimal sustainable suppliers. Therefore, the proposed approach can be applied by managers to evaluate and determine appropriate suppliers in sustainable supplier selection process.

Tribology of thin coatings

Abstract: The fundamentals of coating tribology are presented in a generalised holistic approach to friction and wear mechanisms of coated surfaces in dry sliding contacts. This is based on a classification of the tribological contact process into macromechanical, micromechanical, tribochemical contact mechanisms and material transfer. The tribological contact process is dominated by the macromechanical mechanisms, which have been systematically analysed by using four main parameters: the coating-to-substrate hardness relationship, the film thickness, the surface roughnesses and the debris in the contact. The description covers both soft and hard coatings with thicknesses typically in the range 0.1–50 μm, where the interaction between the coating and the substrate is essential to the tribological behaviour. The concept is supported by experimental observations. The important influence of thin tribo- and transfer layers formed during the sliding action is shown. Optimal surface design both regarding friction and wear can be achieved by new multilayer techniques giving reduced stresses, improved adhesion to substrate, more flexible coatings and harder and smoother surfaces. The differences in contact mechanisms in dry, water- and oil lubricated contacts with coated surfaces is illustrated by experimental results from diamond-like coatings sliding against a steel ball. The mechanisms of the formation of dry transfer- and tribolayers and lubricated boundary and reaction films are discussed.

Zero defect manufacturing: state-of-the-art review, shortcomings and future directions in research

Abstract: This paper provides a literature review on zero defect manufacturing based on the content analysis performed for 280 research articles published from 1987 to 2018 in a variety of academic journals ...