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Article
Publication date: 12 March 2018

X. Canute and M.C. Majumder

Aluminium metal matrix composites are used in automotive and aerospace industries because of their high performance and weight reduction benefits. The current…

Abstract

Purpose

Aluminium metal matrix composites are used in automotive and aerospace industries because of their high performance and weight reduction benefits. The current investigation aims to focus on the development of the stir cast aluminium-boron carbide composites with enhanced mechanical and tribological properties.

Design/methodology/approach

The aluminium-boron carbide composites are produced by stir casting process. Aluminium alloy A356 is chosen as the matrix material and three sets of composites are produced with different weight fractions of boron carbide particles. Higher particle size (63 µm) of boron carbide is chosen as the reinforcement material. Aluminium-boron carbide composites are tested for mechanical and tribological properties. The effect of process parameters like load, speed and percentage of reinforcement on the wear rate are studied using the pin-on-disc method. The interaction of the process parameters with the wear rate is analysed by DesignExpert software using RSM methodology and desirability analysis. The coded levels for parameters for independent variables used in the experimental design are arranged according to the central composite design. The worn surface of the pin is examined using a scanning electron microscope. The phases and reaction products of the composites are identified by X-ray diffraction (XRD) analysis.

Findings

Aluminium-boron carbide composites reveal better mechanical properties compared to monolithic aluminium alloys. Mechanical properties improved with the addition of strontium-based master alloy Al10Sr. The ultimate tensile strength, hardness and compressive strength increase with an increase in the reinforcement content. The wettability of the boron carbide particles in the matrix improved with the addition of potassium flurotitanate to the melt. Uniform dispersion of particles into the alloy during melting is facilitated by the addition of magnesium. Wear resistance is optimal at 8 per cent of boron carbide with a load 20 N and sliding speed of 348 RPM. The wear rate is optimized by the numerical optimization method using desirability analysis. The amount of wear is less in Al-B4C composites when compared to unreinforced aluminium alloy. The wear rate increases with an increase in load and decreases with the sliding speed. The wear resistance increases with an increase in the weight fraction of the boron carbide particles.

Practical implications

The produced Al-B4C composites can retain properties at high temperature. It is used in nuclear and automotive products owing its high specific strength and stiffness. The main applications are neutron absorbers, armour plates, high-performance bicycles, brake pads, sand blasting nozzles and pump seals.

Originality/value

Al/B4C composites have good potential in the development of wear-resistant products.

Details

Industrial Lubrication and Tribology, vol. 70 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 December 2018

Zhentao Yuan, Yehua Jiang, Lu Li and Zulai Li

The purpose of this paper is to study the microstructure and the high-temperature tribology behavior of a high-speed steel (HSS) roller material with boron as the main…

Abstract

Purpose

The purpose of this paper is to study the microstructure and the high-temperature tribology behavior of a high-speed steel (HSS) roller material with boron as the main alloy element under different heat treatments, aiming to provide some theoretical references for its engineering application.

Design/methodology/approach

The samples of high boron HSS were quenched at 900°C, 1,000°C, 1,050°C and 1,150°C. The microstructure, composition and phase composition of this new HSS were analyzed by OM, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometer. The surface hardness and the tribology behavior under high temperature were measured by Rockwell hardness tester and the high-temperature friction and wear tester. The wear morphology was observed by SEM.

Findings

The high-temperature friction coefficient and the relative wear rate of the high boron HSS decrease first, then increase with the rise of the quenching temperature. When the quenching temperature is 1,050°C, both the friction coefficient (0.425) and the relative wear rate (79 per cent) are the smallest. Under the high-temperature friction environment, the high boron HSS mainly includes oxidation wear, adhesive wear and abrasive wear. The effect of abrasive wear is weakened gradually with the rise of the quenching temperature, and the high-temperature wear resistance is improved significantly. Compared with the traditional roll materials, the service life of the new high boron HSS is greatly improved. It is an ideal substitute product for the high chromium cast iron roll.

Originality/value

The boron element replaces other precious metals in high boron HSS, which has the advantage of low production cost, and it has a wide application in the field of roll materials. In this paper, the microstructure, the transformation of hard phases and the high-temperature tribology behavior of this new high boron HSS under different heat treatments were studied, aiming to provide some theoretical references for its engineering application.

Details

Industrial Lubrication and Tribology, vol. 71 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 24 September 2010

Ali Nazari and Shadi Riahi

The aims of this study is to analyze failure of two types of high‐strength low‐alloy (HSLA) steels which are used in wheel bolts 10.9 grade, boron steel and…

Abstract

Purpose

The aims of this study is to analyze failure of two types of high‐strength low‐alloy (HSLA) steels which are used in wheel bolts 10.9 grade, boron steel and chromium‐molybdenum steel, before and after heat treatment.

Design/methodology/approach

The optimum heat treatment to obtain the best tensile behavior was determined and Charpy impact and Rockwell hardness tests were performed on the two steel types before and after the optimum heat treating.

Findings

Fractographic studies show a ductile fracture for heat‐treated boron steel while indicate a semi‐brittle fracture for heat‐treated chromium‐molybdenum steel. Formation of a small boron carbide amount during heat treating of boron steel results in increment the bolt's tensile strength while the ductility did not changed significantly. In the other hand, formation of chromium and molybdenum carbides during heat treating of chromium‐molybdenum steel increased the bolt's tensile strength with a considerable reduction in the final ductility.

Originality/value

This paper evaluates failure analysis of HSLA wheel bolt steels and compares their microstructure before and after the loading regime.

Details

Multidiscipline Modeling in Materials and Structures, vol. 6 no. 3
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 30 May 2019

Gaurav Arora and Satpal Sharma

This paper aims to produce hybrid reinforcement for the development of aluminium matrix composites using ball-billing technique to avoid or reduce the problem of…

Abstract

Purpose

This paper aims to produce hybrid reinforcement for the development of aluminium matrix composites using ball-billing technique to avoid or reduce the problem of agglomeration of the reinforcement during casting.

Design/methodology/approach

In the present investigation, a mixture of silicon carbide (SiC) and rice husk ash (RHA) powder in equal weight percentage ratio 4:4 (1:1) was alloyed mechanically in a ball-mill at distinct milling times of 15, 30, 45, 60 and 75 h. Morphological Characterization and density measurements of the ball-milled powder were carried out after different intervals of milling times.

Findings

The results revealed that the process of ball milling is a novel technique for the conversion of two or more powders in to an integer powder and reduces the problem of agglomeration also. The density measurement results revealed that an increasing trend of density initially and reduction of the density with the increase of milling time. The density value of the combined particles became comparable to the density of aluminium at the milling time of 75 h for the equal weight percentage ratio 4:4 (1:1) of SiC and RHA.

Originality/value

The manuscript highlights the research work related to the development of the reinforcement for the aluminium hybrid composites by ball milling process. The use of this process for the development of the reinforcement not only reduces the problem of the agglomeration but reduces the density mismatch of the reinforcement and matrix material also.

Details

World Journal of Engineering, vol. 16 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 November 1959

Describes a technique, currently used at General Motors, which contains some of the elements of operations research and has effected important reductions in costs. The…

Abstract

Describes a technique, currently used at General Motors, which contains some of the elements of operations research and has effected important reductions in costs. The technique contains seven steps: (i) determine problem or objective, (ii) study conditions existing, (iii) plan possible solutions, (iv) evaluate possible solutions, (v) recommend action, (vi) follow up to assure action, (vii) check results. The procedure followed at each step is outlined. The investigation is carried out by a special Planning Team. This team consults other staff involved as may be necessary. During any investigation of existing plant the aim is that production should continue at a minimum cost.

Details

Aircraft Engineering and Aerospace Technology, vol. 31 no. 11
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 April 2005

Jaroslav Mackerle

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming…

Abstract

Purpose

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

Design/methodology/approach

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Findings

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Originality/value

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

Details

Engineering Computations, vol. 22 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 16 April 2020

Rahul Dev Gupta, Pardeep Gupta and Rajesh Khanna

This paper consolidates and presents the results of a work conducted to fabricate micro-channels on titanium grade-2 material by ultrasonic machining process (USM). In…

Abstract

Purpose

This paper consolidates and presents the results of a work conducted to fabricate micro-channels on titanium grade-2 material by ultrasonic machining process (USM). In this research, the effects of important USM parameters, namely, kind of abrasives and its size, concentration of slurry, USM power rating and feed rate, have been probed on micro-channels quality for average surface roughness and process throughput in the form of material removal rate.

Design/methodology/approach

Multiple micro-channels on commercially pure titanium (i.e. Ti grade-2) have been fabricated in a single pass by employing micro-tool based USM process. Taguchi-based L18 (mixed level) OA has been selected for experimental design. Analysis of variance (ANOVA) study and regression modeling have also been done. Non-Dominated Sorting Genetic Algorithm (NSGA-II) has been used for process optimization to get optimum values of material removal rate (MRR) and surface roughness (SR).

Findings

The influence of important USM variables on SR and MRR have been investigated, and NSGA-II-based multi-response optimization has been done. The best surface roughness values obtained via NSGA-II solution for SiC and B4C are 0.354 µm and 1.303 µm, respectively. Scanned electron microscopic investigation proves the fabrication of micro-channels with smooth surfaces, and minimum burrs and other defects. The material removed from the surface was due to ductile fractures.

Originality/value

Miniaturization is a modern trend these days to solve many precision, scientific and industrial problems. To manufacture precise micro-products, shapes and features, advanced and micro-machining processes can play a very prominent role. Micro-channels are typical micro-features required in micro-fluidic applications like micro heat exchangers and micro-pumps. Exhaustive review of existing research work indicated that precision micromachining of various materials can be effectively performed using USM, though not much work has been undertaken to explore the feasibility of multiple micro-channels in a single run using USM. The current work fulfills the gap, where multiple micro-channels on commercially pure titanium (i.e. Ti grade-2) have been fabricated in a single pass by employing micro-tool-based USM process.

Details

Grey Systems: Theory and Application, vol. 10 no. 2
Type: Research Article
ISSN: 2043-9377

Keywords

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Article
Publication date: 13 April 2015

Adalet Zeren

– The purpose of this paper is to understand the effect of graphite content on the properties of aluminum alloy/silicon carbide/granite (Al/SiC/Gr) composites.

Abstract

Purpose

The purpose of this paper is to understand the effect of graphite content on the properties of aluminum alloy/silicon carbide/granite (Al/SiC/Gr) composites.

Design/methodology/approach

Hardness and wear tests were applied to the powder metallurgical composites, and microstructural characterization was conducted.

Findings

Optimum graphite content for maximum wear resistance is reported as weight 6 per cent.

Originality/value

Results of this study may help light weight Al/SiC/Gr composites to be used in different industrial applications.

Details

Industrial Lubrication and Tribology, vol. 67 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 April 1994

Terry Ford

Organized by the Institute of Materials, this latest MMC conference was subtitled “Design and Innovation” and attracted delegates from research bodies, universities and…

Abstract

Organized by the Institute of Materials, this latest MMC conference was subtitled “Design and Innovation” and attracted delegates from research bodies, universities and industry. It enabled exchanges of information on these materials to be made and provided a view of the latest work being undertaken, as well as prospects for the future. The problems associated with the production of MMCs, as well as their potential, were explored, with a range of applications envisaged. As far as their possible use in aerospace is concerned, this is currently limited in scope, but developments and extensive testing will enable the necessary qualification criteria to be established and lead to a variety of uses.

Details

Aircraft Engineering and Aerospace Technology, vol. 66 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 December 2005

R.I. Amaro, R.C. Martins, J.O. Seabra, S. Yang, D.G. Teer and N.M. Renevier

Provide tribological information about the applicability of multi‐layer carbon‐chromium composite coatings to gears. Discuss the protection provided against scuffing…

Abstract

Purpose

Provide tribological information about the applicability of multi‐layer carbon‐chromium composite coatings to gears. Discuss the protection provided against scuffing failures, wear and the influence on gear power losses.

Design/methodology/approach

Several screening tests, such as Rockwell indentations, ball cratering, pin‐on‐disc and reciprocating wear tests, were performed in order to evaluate the adhesion to the substrate and the tribological performance of the carbon/chromium composite coating. Afterwards, twin‐disc tests were performed at high contact pressure and high slide‐to‐roll ratios to confirm the good adhesive and tribological properties of the coating under operating conditions similar to those found in gears. Gear tests were performed in the FZG machine in order to evaluate the anti‐scuffing performance of the carbon/chromium coating using additive free gear oils. Finally, the carbon/chromium composite coating was also applied to the gearing in a gearbox and its influence on the gearbox efficiency was analysed.

Findings

The C/Cr has got very good adhesion to the steel substrate, provides low friction coefficients between contacting solids in relative movement, gives excellent protection against scuffing and wear reduction in gears, and promotes a slight improvement of the gears efficiency.

Research limitations/implications

The protection of this carbon/chromium coating against gear micro‐pitting should be investigated.

Practical implications

This study confirms the applicability of this coating to industrial gear applications, especially in two particular applications: severe applications involving high contact pressures and high sliding, frequent start‐ups and inefficient lubrication; and acting as tribo‐reactive material and substituting non‐biodegradable and toxic additives in environmental lubricants.

Originality/value

This work validates and quantifies the influence of this C/Cr multi‐layer composite coating in gear applications in terms of adhesion to the substrate, anti‐scuffing performance and efficiency.

Details

Industrial Lubrication and Tribology, vol. 57 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

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