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1 – 10 of over 13000Dhafer Abdul‐Ameer Shnawah, Mohd Faizul Mohd Sabri, Irfan Anjum Badruddin and Fa Xing Che
The purpose of this paper is to investigate the effect of Al addition on the bulk alloy microstructure and tensile properties of the low Ag‐content Sn‐1Ag‐0.5Cu (SAC105) solder…
Abstract
Purpose
The purpose of this paper is to investigate the effect of Al addition on the bulk alloy microstructure and tensile properties of the low Ag‐content Sn‐1Ag‐0.5Cu (SAC105) solder alloy.
Design/methodology/approach
The Sn‐1Ag‐0.5Cu‐xAl (x=0, 1, 1.5 and 2 wt.%) bulk solder specimens with flat dog‐bone shape were used for tensile testing in this work. The specimens were prepared by melting purity ingots of Sn, Ag, Cu and Al in an induction furnace. Subsequently, the molten alloys were poured into pre‐heated stainless steel molds, and the molds were naturally air‐cooled to room temperature. Finally, the molds were disassembled, and the dog‐bone samples were removed. The solder specimens were subjected to tensile testing on an INSTRON tester with loading rate 10−3 s−1. The microstructural analysis was carried out using scanning electron microscopy/Energy dispersive X‐ray spectroscopy. Electron Backscatter Diffraction (EBSD) analysis was used to identify the IMC phases. To obtain the microstructure, the solder samples were prepared by dicing, molding, grinding and polishing processes.
Findings
The addition of Al to the SAC105 solder alloy suppresses the formation of Ag3Sn and Cu6Sn5 IMC particles and leads to the formation of larger Al‐rich and Al‐Cu IMC particles and a large amount of fine Al‐Ag IMC particles. The addition of Al also leads to refining of the primary β‐Sn grains. The addition of Al results in a significant increase on the elastic modulus and yield strength. On the other hand, the addition of Al drastically deteriorates the total elongation.
Originality/value
The addition of Al to the low Ag‐content SAC105 solder alloy has been discussed for the first time. This work provides a starting‐point to study the effect of Al addition on the drop impact and thermal cycling reliability of the SAC105 alloy.
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The effects of a number of metals and alloys on the thermal stability of Avtur 50 have been evaluated from ASTM‐CRC and high temperature coker tests. The materials tested are used…
Abstract
The effects of a number of metals and alloys on the thermal stability of Avtur 50 have been evaluated from ASTM‐CRC and high temperature coker tests. The materials tested are used in current aircraft fuel systems or are possible alternatives for fuel systems of supersonic aircraft where they will be in contact with hot fuel. The alloys currently used in aircraft fuel systems have been classified and their probable effects on the stability of hot fuel listed. A number of the materials affected stability adversely, particularly alloys containing significant amounts of copper, and the use of these should be avoided. The pick‐up of copper by Avtur 50 at ambient temperature from alloys such as brass and gun‐metal has also been investigated. The results indicated that sufficient copper to affect thermal stability adversely is readily picked up from these alloys.
This paper describes the effect of alloying elements such as Nb and Ga on the corrosion behaviour of Nd‐Fe‐B permanent magnetic alloy. The results revealed that the alloying…
Abstract
This paper describes the effect of alloying elements such as Nb and Ga on the corrosion behaviour of Nd‐Fe‐B permanent magnetic alloy. The results revealed that the alloying elements are not helpful in improving the corrosion resistance of the base magnet; rather their presence makes the base alloy highly vulnerable to corrosion in acidic environments. In particular, Nb addition is more detrimental to corrosion as was evidenced by potentiodynamic, cyclic polarisation, Ecorr vs time, electrochemical impedance and SEM results. The studies also showed that the degradation of the alloys with and without alloying addition takes place due to preferential dissolution of grain boundaries.
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This paper aims to investigate the effects of second phase precipitate size on microstructure, hardness, density, corrosion and electrical conductivity of 7075 aluminum alloy…
Abstract
Purpose
This paper aims to investigate the effects of second phase precipitate size on microstructure, hardness, density, corrosion and electrical conductivity of 7075 aluminum alloy fabricated by the powder metallurgy method and aged at 120°C for various aging periods.
Design/methodology/approach
For the aging process (T6), these alloys were solution-treated at 485°C for 2 h, quenched, aged at 120°C for four various periods and finally air cooled. After the aging process, these alloys were examined with scanning electron microscope, X-ray diffraction, density and hardness measurements. The corrosion tests were carried out using the potentiodynamic polarization technique; electrical conductivity values were measured as IACS%.
Findings
Results showed that the precipitate size increased with increasing aging period and the maximum precipitate size was achieved for the sample aged for 28 h. The maximum hardness was attained for the sample aged for 24 h, while the same specimen obtained the lowest electrical conductivity and corrosion resistance.
Originality/value
In this research, second phase precipitates of heat treatment processing affected the electrical conductivity and corrosion behavior of the 7075 aluminum alloy. Also it is understood that the heat treatment period is an effective parameter on these properties.
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R.J. Smith, G.J. Lewi and D.H. Yates
Since the development of the Nimonic1 alloys for Sir Frank Whittle’s first jet engine, Henry Wiggin Ltd, now part of Special Metals Corporation, has been involved with the design…
Abstract
Since the development of the Nimonic1 alloys for Sir Frank Whittle’s first jet engine, Henry Wiggin Ltd, now part of Special Metals Corporation, has been involved with the design and improvement of nickel alloys for aerospace engineering. Whilst much of this work continues to be in relation to alloys for the high strength/high temperature applications of turbine blades, discs, seals, rings and casings of aero engines, nickel alloys are being utilised for other key aerospace engineering areas such as tooling for composite manufacture. The focus of this paper is on four recent developments in nickel alloys for aerospace engineering, namely: disc alloys; low expansion superalloys; Inconel alloy 718SPF – a nickel base superalloy capable of being superplastically formed; Nilo (low expansion alloys) for composite tooling.
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P.M. Bartle and K.G. Kent
THE alloys under consideration contain only zinc and magnesium as the major alloying additions. The total alloy content varies between 5 and 7 per cent whereas the high strength…
Abstract
THE alloys under consideration contain only zinc and magnesium as the major alloying additions. The total alloy content varies between 5 and 7 per cent whereas the high strength aircraft alloys have a total content of 8 to 10 per cent and may also contain up to 2 per cent of copper. A wide range of mechanical properties can be obtained with the weldable alloys and some of these properties closely approach those of the aircraft alloys. Problems associated with weld metal cracking and heat affected zone recovery arc normally severe with age hardening aluminium alloys but are greatly attenuated with the weldable alloys.
S.A. Kori, T.M. Chandrashekharaiah, V. Auradi and V.R. Kabadi
This paper aims to study the effect of Al‐Ti‐B grain refiners on the wear behaviour of hypoeutectic (Al‐0.2, 2, 3, 4, 5 and 7Si alloys) Al‐Si alloys against steel counterface…
Abstract
Purpose
This paper aims to study the effect of Al‐Ti‐B grain refiners on the wear behaviour of hypoeutectic (Al‐0.2, 2, 3, 4, 5 and 7Si alloys) Al‐Si alloys against steel counterface using a Pin‐On‐Disc machine under dry sliding conditions.
Design/methodology/approach
In the present study, Al‐5Ti‐1B and Al‐1Ti‐3B grain refiners were used for the refinement of α‐Al dendrites in hypoeutectic Al‐Si alloys. Various parameters such as alloy composition, normal pressure, sliding speed and sliding distance were studied on Al‐Si alloys. Worn surfaces were characterized by SEM/EDX microanalysis.
Findings
Wear resistance of hypoeutectic Al‐Si alloys increases with the addition of Al‐Ti‐B refiners when compared with the absence of grain refiner.
Research limitations/implications
The effects of normal pressure, sliding speed and sliding distance were studied by varying one parameter and keeping constant the other two parameters.
Originality/value
This paper provides information on improvement in wear properties of Al‐Si alloys by the addition of Al‐Ti‐B grain refiners. The effects of silicon and grain refiners containing Ti/B play a vital role and are responsible for the wear resistance of the alloys, which helps the industrialists in manufacturing Al‐Si alloy components.
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Basavaraj Mallappa Ganiger, Chandrashekharaiah Tumbigeri Mata, H R Manohara and T B Prasad
The main purpose of the research paper is to study the effect of refinement of primary silicon on sliding wear behavior of commercially available LM-28 alloy and correlate these…
Abstract
Purpose
The main purpose of the research paper is to study the effect of refinement of primary silicon on sliding wear behavior of commercially available LM-28 alloy and correlate these with the micro-structural and mechanical properties. It is well known that the refinement of primary silicon increases the toughness, ultimate tensile stress (UTS) and wear resistance of the Al-Si alloys at ambient temperature. But exact addition level is not clearly mentioned in the paper; hence, the present paper throws light on the addition level for refinement of primary silicon present in LM-28 alloy.
Design/methodology/approach
In the present paper, commercially available LM-28 alloy was prepared in the laboratory before and after the addition of Cu-P master alloy. Further wear studies will be carried out at room temperature. Wear properties are correlated with microstructure and mechanical properties.
Findings
Improvements in mechanical properties were observed after refinement of the primary silicon present in LM-28 alloy.
Research limitations/implications
Further studies are required regarding in-depth investigation of refinement of primary silicon and its effects on the life of the components prepared by this alloy.
Practical implications
The data obtained from the research paper help the manufacturers of automotive, aerospace and marine components, such as pistons, cylinder heads and blocks, etc.
Social implications
The present research work will be an essential information required for the students of undergraduate, postgraduate and research scholars to carry out research at an R&D centre.
Originality/value
Experiments are conducted at an R&D centre and analyses were carried out for structural changes, mechanical properties and wear properties. Further, the results are compared with other researcher’s data.
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Guidelines for making a wise choice when selecting high temperature alloys are provided. Four groups of alloys are discussed, along with helpful selection criteria. Substantial…
Abstract
Guidelines for making a wise choice when selecting high temperature alloys are provided. Four groups of alloys are discussed, along with helpful selection criteria. Substantial benefits accrue from contemporary alloy manufacturing techniques. Process databases and state‐of‐the‐art forging equipment significantly impact product quality, consistency and cost effectiveness. Finally, the author suggests that the elimination of unnecessary test requirements offers potential for savings in time and money. He feels that alloy integrity can be assured by any producer who can demonstrate narrow limits of compositional control, as well as melting, remelting and hot working controls.
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Selecting the most suitable, cost‐efficient alloy for a given application should not be difficult if the methodology described in this paper is followed. The first step is to…
Abstract
Selecting the most suitable, cost‐efficient alloy for a given application should not be difficult if the methodology described in this paper is followed. The first step is to identify those alloys with the desired corrosion resistance. Factors other than chemical composition have a bearing on an alloy’s corrosion resistance. Service environment and nature of the product application must also be considered. These conditions are discussed in the text. Consideration should be given to other key issues such as mechanical properties required as well as method of fabrication, design, condition and availability of the candidate alloy. To simplify selection, the author discusses severe corrodents and aggressive environments that are commonly encountered in the process industries, and describes the characteristics of alloys that might be considered for each type of corrosive service. Cross referenced charts position these alloys to show their relative resistance to each type of corrosion attack. While the paper is not designed to replace the technical expertise of a corrosion engineer, the author feels it can serve as a good starting point in the alloy selection process.