Uday Hameed Farhan, Majid Tolouei-Rad and Adam Osseiran
The purpose of this paper is to develop a model of analytic hierarchy process (AHP), a multiple criteria decision-making method, to assist selecting suitable machine…
Abstract
Purpose
The purpose of this paper is to develop a model of analytic hierarchy process (AHP), a multiple criteria decision-making method, to assist selecting suitable machine configurations for special purpose machines (SPMs) from available alternatives.
Design/methodology/approach
The necessary criteria and sub-criteria were identified and used in the developed model. The assessment process was carried out by constructing the hierarchy of four levels. Then, pairwise comparison matrices were created for each level to compute the weights for the alternatives. The model was programmed and implemented by software for practical use.
Findings
Different scenarios were obtained from the assessment process of the developed AHP model showing the influence of changing the relevant importance of the elements in the hierarchy on the selection of SPMs configurations. Selection of the suitable scenario was also affected by some factors of manufacturing preferences and industry recommendations such as cost and production rate.
Originality/value
This is a new application of AHP method which assists decision makers to select suitable configurations for SPMs, and reduce the time required for designing SPMs.
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Uday Hameed Farhan, Majid Tolouei-Rad and Adam Osseiran
The purpose of this paper is to develop an assembly modelling approach to be applied with a software package, to assist in the design and assembly of special purpose machines…
Abstract
Purpose
The purpose of this paper is to develop an assembly modelling approach to be applied with a software package, to assist in the design and assembly of special purpose machines (SPMs).
Design/methodology/approach
A database of SPM elements was established, and an assembly relationships graph was created. Mating conditions were identified between the SPM elements, and their assembly constraints were extracted and implemented in SolidWorks application programming interface.
Findings
The implementation of this assembly modelling approach was validated by selecting SPM layouts as examples. A significant reduction in the assembly time was achieved compared to the traditional assembly procedure for the same examples.
Originality/value
This is a new application of assembly modelling that assists engineers and designers in the design and assembly processes of SPMs. This approach can also be applied to other machine tools with similar attributes.
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Muhammad Aamir, Riaz Muhammad, Majid Tolouei-Rad, Khaled Giasin and Vadim V. Silberschmidt
The research on lead-free solder alloys has increased in past decades due to awareness of the environmental impact of lead contents in soldering alloys. This has led to the…
Abstract
Purpose
The research on lead-free solder alloys has increased in past decades due to awareness of the environmental impact of lead contents in soldering alloys. This has led to the introduction and development of different grades of lead-free solder alloys in the global market. Tin-silver-copper is a lead-free alloy which has been acknowledged by different consortia as a good alternative to conventional tin-lead alloy. The purpose of this paper is to provide comprehensive knowledge about the tin-silver-copper series.
Design/methodology/approach
The approach of this study reviews the microstructure and some other properties of tin-silver-copper series after the addition of indium, titanium, iron, zinc, zirconium, bismuth, nickel, antimony, gallium, aluminium, cerium, lanthanum, yttrium, erbium, praseodymium, neodymium, ytterbium, nanoparticles of nickel, cobalt, silicon carbide, aluminium oxide, zinc oxide, titanium dioxide, cerium oxide, zirconium oxide and titanium diboride, as well as carbon nanotubes, nickel-coated carbon nanotubes, single-walled carbon nanotubes and graphene-nano-sheets.
Findings
The current paper presents a comprehensive review of the tin-silver-copper solder series with possible solutions for improving their microstructure, melting point, mechanical properties and wettability through the addition of different elements/nanoparticles and other materials.
Originality/value
This paper summarises the useful findings of the tin-silver-copper series comprehensively. This information will assist in future work for the design and development of novel lead-free solder alloys.
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Muhammad Aamir, Majid Tolouei-Rad, Israr Ud Din, Khaled Giasin and Ana Vafadar
Tin-Silver-Copper is widely accepted as the best alternative to replace Tin-Lead solders in microelectronics packaging due to their acceptable properties. However, to overcome…
Abstract
Purpose
Tin-Silver-Copper is widely accepted as the best alternative to replace Tin-Lead solders in microelectronics packaging due to their acceptable properties. However, to overcome some of the shortcomings related to its microstructure and in turn, its mechanical properties at high temperature, the addition of different elements into Tin-Silver-Copper is important for investigations. The purpose of this paper is to analyse the effect of lanthanum doping on the microstructure, microhardness and tensile properties of Tin-Silver-Copper as a function of thermal aging time for 60, 120 and 180 h at a high temperature of 150°C and at high strain rates of 25, 35 and 45/s.
Design/methodology/approach
The microstructure of un-doped and Lanthanum-doped Tin-Silver-Copper after different thermal aging time is examined using scanning electron microscopy followed by digital image analyses using ImageJ. Brinell hardness is used to find out the microhardness properties. The tensile tests are performed using the universal testing machine. All the investigations are done after the above selected thermal aging time at high temperature. The tensile tests of the thermally aged specimens are further investigated at high strain rates of 25, 35 and 45/s.
Findings
According to the microstructural examination, Tin-Silver-Copper with 0.4 Wt.% Lanthanum is found to be more sensitive at high temperature as the aging time increases which resulted in coarse microstructure due to the non-uniform distribution of intermetallic compounds. Similarly, lower values of microhardness, yield strength and ultimate tensile strength come in favours of 0.4 Wt.% Lanthanum added Tin-Silver-Copper. Furthermore, when the thermally aged tensile specimen is tested at high strains, two trends in tensile curves of both the solder alloys are noted. The trends showed that yield strength and ultimate tensile strength increase as the strain rate increase and decrease when there is an increase in thermal aging.
Originality/value
The addition of higher supplement (0.4 Wt.%) of Lanthanum into Tin-Silver-Copper showed a lower hardness value, yield strength, ultimate tensile strength, ductility, toughness and fatigue in comparison to un-doped Tin-Silver-Copper at high temperature and at high strain rates. Finally, simplified material property models with minimum error are developed which will help when the actual test data are not available.
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RamezanAli Mahdavinejad, Majid Tolouei‐Rad and Hassan Sharifi‐Bidgoli
The purpose of the research is to analyze instability in ED machining of silicon carbide (SiC) due to heat generation in the workpiece body. The results can be used in selecting a…
Abstract
Purpose
The purpose of the research is to analyze instability in ED machining of silicon carbide (SiC) due to heat generation in the workpiece body. The results can be used in selecting a convenient machining set up.
Design/methodology/approach
Various researches (1978‐2002) have shown the importance of SiC industrial applications in many branches of technology. Instability process in EDM as a very good candidate for SiC machining is still a serious problem. Joule heating generation in SiC body due to its very high electrical resistivity is a very important point, which needs to be considered. From this point of view, the machining set up can be optimized.
Findings
The results of this research provide consideration of some factors to prevent against heat loss and voltage drop in SiC body during ED machining process. This leads the process to be more stable.
Originality/value
According to the results of this research, Joule heating due to the voltage drop in SiC body is a main factor in ED machining of this material. Therefore, some techniques as voltage injection are recommended.