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Numerical and Response Surface Interactions for Optimizing Extrusion Parameters
Gundu David Terfa,
Tuleun Livinus Tyovenda,
Agber Jonathan Uhaa
Issue:
Volume 4, Issue 3, May 2015
Pages:
143-148
Received:
24 March 2015
Accepted:
8 April 2015
Published:
21 April 2015
Abstract: An experimental program was undertaken to extrude a lead alloy on ELECompact-1500 compression machine. Extrusion variables were extrude diameter (d), die bearing length (h), and included die entrant angle Ө = 90o. Using experimental values, numerical models were obtained to describe the relationship between extrusion variables and extrusion pressure and extrude deflection. The numerical models were then used to obtain the response pressure predictions for aluminum alloy. Results of validation tests indicated good correlation between predicted and experimental values. The predictions also compare favorably with values obtained by a similar second-order modified upper bound model frequently used in industry for estimating extrusion loads with prediction errors below 4%. Surface responses graphs of extrusion pressure and extrude deflection were also used to define the optimized field for interaction of extrusion parameters for minimizing extrusion loads and controlling extrudes deflection or bending. Owing to fewer input variables, the proposed models were considered convenient options for a quick estimate of extrusion loads and product curvature.
Abstract: An experimental program was undertaken to extrude a lead alloy on ELECompact-1500 compression machine. Extrusion variables were extrude diameter (d), die bearing length (h), and included die entrant angle Ө = 90o. Using experimental values, numerical models were obtained to describe the relationship between extrusion variables and extrusion pressur...
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Application of Multi-Criteria Decision Making Optimization Tool for Determining Mild Steel Weld Properties and Process Parameters Using the TOPSIS
Joseph Achebo,
Monday Omoregie
Issue:
Volume 4, Issue 3, May 2015
Pages:
149-158
Received:
8 February 2015
Accepted:
24 March 2015
Published:
24 April 2015
Abstract: Several different processes and models have been adopted for the optimization of weld deposit quality of mild steel joints. These various processes and models have been used continually over the decades to find new ways of improving weld deposit quality, with the ultimate aim of improving the service life of the resulting weld joints. This quest to find ways of improving weld deposit quality has resulted in the use of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). TOPSIS is one such technique used for solving multi criteria problems. It is based on the concept that the optimal alternative should have the shortest distance from the positive ideal solution, and the farthest distance from the negative ideal solution. From applying the TOPSIS technique, it was found that weldment 9 has the best weld mechanical properties with a Brinell hardness number (BHN) of 216, Ultimate tensile strength (UTS) of 600MPa, Charpy V-notch (CVN) impact energy of 90J, and a percentage elongation of 23%. Also the relationship between the input parameters and the output parameters was examined. It is therefore, concluded that TOPSIS has successfully optimized the input process parameters which has produced the most desired mechanical properties. In this study a step by step approach for the application of the TOPSIS technique is adopted.
Abstract: Several different processes and models have been adopted for the optimization of weld deposit quality of mild steel joints. These various processes and models have been used continually over the decades to find new ways of improving weld deposit quality, with the ultimate aim of improving the service life of the resulting weld joints. This quest to...
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Synthesis of High Quality LaCoO3 Crystals Using Water Based Sol-Gel Method
Issue:
Volume 4, Issue 3, May 2015
Pages:
159-164
Received:
28 March 2015
Accepted:
15 April 2015
Published:
24 April 2015
Abstract: Lanthanum cobaltite (LaCoO3) crystalline material is a promising material for its interesting electrical, magnetic, catalytic and thermoelectric properties. In this study, LaCoO3 powders were synthesized by water based sol-gel method using metal nitrates as precursors and citric acid as the chelating agent at room temperature. The dried powders were amorphous and their thermal decomposition occurs stepwise upon heating to 400 °C. Pure perovskite-type single phase LaCoO3 polycrystals are formed after heating at 600 °C. The pallets prepared from calcined powers were sintered at 1200 °C and crystalline pallets were characterized for investigation of electrical, optical and thermoelectric properties. The obtained results revealed that the prepared samples were highly crystalline with large cation ordering. The sol-gel method found to be efficient for much production of a lot of crystalline transition metal oxides at low cost.
Abstract: Lanthanum cobaltite (LaCoO3) crystalline material is a promising material for its interesting electrical, magnetic, catalytic and thermoelectric properties. In this study, LaCoO3 powders were synthesized by water based sol-gel method using metal nitrates as precursors and citric acid as the chelating agent at room temperature. The dried powders wer...
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Investigation of Wettability of Lead Free-Solder on Bare Copper and Organic Solder Preservatives Surface Finishes
Gabriel Takyi,
Peter Kojo Bernasko
Issue:
Volume 4, Issue 3, May 2015
Pages:
165-172
Received:
8 April 2015
Accepted:
20 April 2015
Published:
30 April 2015
Abstract: Wettability plays an important role in the integrity of solder joints especially in critical safety operations. It helps in attaining successful soldering and reliable solder joints. The angle of wettability determines the degree of solder contact and strength of the solder joint. Moreover, the contact angle between the solid substrate and the molten solder determines the interconnection reliability. This paper focuses on the wettability of lead free solder on OSP and bare copper substrate surface finishes. The wetting behaviour of lead free solder pastes on bare copper board and Organic Solderability Preservatives (OSPs) substrates were investigated. The test vehicles consist of FR4 PCB single sided 100% copper clad with a thick film metallization and FR4 PCB single sided OSP. The substrate dimension was 100 mm×160 mm×1.6 mm. A total of 480 bumps of Lead-free solder pastes (96Sn-3.8Ag-0.5Cu and 96.5Sn-3.0Ag-0.7Cu alloy composition) were deposited for the investigation. The printing parameters and their values for the experiments include print gap of 0 mm, squeegee speed of 20 mm/s, pressure of 8kg and separation speed of 3 mm/sec. The pastes are screen printed on the substrates using 0.125mm thick stencil mounted on DEK 260 series printing machine. After the stencil printing process, the solder bumps deposited on the substrates were reflowed using a Novostar 2000HT horizontal convention reflow oven with 4-stage (preheat-soak-reflow-cooling). The FTA188 Analyser was employed for measuring the angle of contact between the substrates and the bumps. The results showed that the wetting contact angle of copper surface finish is lower as compared to the organic solderability preservatives surface finish and the wetting angle decreases as the contact surface area increases.
Abstract: Wettability plays an important role in the integrity of solder joints especially in critical safety operations. It helps in attaining successful soldering and reliable solder joints. The angle of wettability determines the degree of solder contact and strength of the solder joint. Moreover, the contact angle between the solid substrate and the molt...
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The Life Predicting Calculations Based on Conventional Material Constants from Short Crack to Long Crack Growth Process
Issue:
Volume 4, Issue 3, May 2015
Pages:
173-188
Received:
15 March 2015
Accepted:
22 April 2015
Published:
4 May 2015
Abstract: To use the theoretical approach, to adopt the multiplication-method of two-parameters, by means of the traditional and the modern material constants, thereby to establish some of new calculation models in all crack growth process. In which are the equations of the driving forces, the crack-growth-rate-linking-equation in whole process, and the life predictions; and to propose yet some calculating expressions under different loading conditions. For key material parameters give their new concepts, and provide new functional formulas, define their physical and geometrical meanings. For the transition crack size from micro to macro crack growth process, provide concrete calculation processes and methods. Thereby realize the lifetime predicting calculations in whole process based on conventional materials constants and by the multiplication method of two parameters.
Abstract: To use the theoretical approach, to adopt the multiplication-method of two-parameters, by means of the traditional and the modern material constants, thereby to establish some of new calculation models in all crack growth process. In which are the equations of the driving forces, the crack-growth-rate-linking-equation in whole process, and the life...
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Effect of Chemical Treatments on the Physicochemical and Tensile Properties of Cow Hair Fibre for Low Load Bearing Composites Development
Isiaka Oluwole Oladele,
Jimmy Lolu Olajide,
Adekunle Sulaiman Ogunbadejo
Issue:
Volume 4, Issue 3, May 2015
Pages:
189-197
Received:
27 April 2015
Accepted:
5 May 2015
Published:
15 May 2015
Abstract: This research has investigated the influence of H2O2, KOH and NaOH treatments on the physicochemical and tensile properties of cow hair fibres for composites applications. The chemical treatments for this present study were prepared with predetermined molar concentrations of 0.10, 0.15 and 0.2 M respectively. The physicochemical properties of the cow hair fibres were established using proximate analysis and the tensile properties of the fibres were evaluated with the aid of an Instron universal testing machine. From the results of the proximate analysis, it was observed that, with increase in the concentration of the H2O2 treatment there was increase in the crude protein and moisture contents and decrease in the ash content of the fibres. However, the KOH and NaOH treatments showed an opposite trend. Also, from the tensile test results, it was observed that the chemical treatments aided the enhancement of ultimate tensile and yield strengths of the fibres in comparison with the untreated fibres while tensile strain at break was enhanced by 0.1 and 0.2 M of KOH as well as 0.2 M of NaOH treatments. The results of this research have shown that proper chemical treatment can enhance the properties of cow hair fibres for composites applications.
Abstract: This research has investigated the influence of H2O2, KOH and NaOH treatments on the physicochemical and tensile properties of cow hair fibres for composites applications. The chemical treatments for this present study were prepared with predetermined molar concentrations of 0.10, 0.15 and 0.2 M respectively. The physicochemical properties of the c...
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Optimum Composition for High Strength Aluminium Flux Using the Gauss-Jordan Row Operation Model
Joseph Achebo,
Monday Omoregie
Issue:
Volume 4, Issue 3, May 2015
Pages:
198-202
Received:
8 February 2015
Accepted:
23 March 2015
Published:
14 May 2015
Abstract: Globally, aluminium and its alloys are generally regarded as materials that are difficult to weld. Research is ongoing with a view to finding newer and better ways to repair or weld these alloys. Consequently various mathematical models are currently being adapted to formulate new compositions for aluminium welding fluxes. In this study, a new flux was developed for the welding of high strength aluminium alloy using the Gauss Jordan Row Operation model. By applying this model, an optimum composition of 39% NaCl , 20.5% CaCl2 , 20.5% KCl, 6% CaF2, and 14% 3NaFAlF3, was obtained. The weldment which resulted from the application of this optimum flux was subjected to certain mechanical tests, such as the tensile test, hardness test, and micro-structural analysis. The ultimate tensile strength of the weld was found to be 428 MPa, 0.2% proof stress of 305 MPa, and a Brinell hardness number of 94. These values compare well with published values in literature. Also from the micro-structural analysis, the weld is confirmed to be of good quality. A systematic (step by step) approach has been applied in this research work and found to be very rewarding.
Abstract: Globally, aluminium and its alloys are generally regarded as materials that are difficult to weld. Research is ongoing with a view to finding newer and better ways to repair or weld these alloys. Consequently various mathematical models are currently being adapted to formulate new compositions for aluminium welding fluxes. In this study, a new flux...
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Modeling of Conventional Autoclave Curing of Unsaturated Polyester Based Composite Materials as Production Process Guide
Adefemi Adeodu,
Christopher Anyaeche,
Oluleke Oluwole,
Samuel Afolabi
Issue:
Volume 4, Issue 3, May 2015
Pages:
203-208
Received:
1 June 2014
Accepted:
1 July 2014
Published:
26 May 2015
Abstract: Modeling of composite curing process is required prior to composite production as this would help in establishing correct production parameters thereby eliminating costly trial and error runs. Determining curing profile temperatures from experiment is a huge challenge which in itself is like re-inventing the wheel of trial and error, when mathematical models of physical, chemical and kinetic properties of the constituent materials could be used in modeling the cure situation to some degree of trust. This work has modeled two types of polymer based composite materials (Aluminum filled polyester and carbon-black filled polyester) representing polymer-metal and polymer-organic composites in order to predict the possible trends during conventional autoclave heating with regards to effect of heating rate on degree of cure of the composites. The numerical models were constructed by taking into account the heat transferred by conduction through the resin/filler mixture, as well as kinetic heat generated by cure reaction. The numerical solution of the mathematical models presented were discretized using forward finite differences of the Runge Kuta Method and finally solved using MATLAB® C programming language. It was observed that Aluminum filled polyester composite responded faster to heat input- induced curing and as such was able to cure faster than polyester –carbon black composite which had much slower cure –heat input response. This implies that in the production process of polymer-organic composites, faster heating rate was necessary to input heat into the process as there was no heat of reaction released during the cure process whereas, polymer-metal composites release heat of reaction contributing to the quick transfer of heat into the metal components causing the metal components to behave as points of adhesion to the polymer matrix thereby necessitating a slower heating rate.
Abstract: Modeling of composite curing process is required prior to composite production as this would help in establishing correct production parameters thereby eliminating costly trial and error runs. Determining curing profile temperatures from experiment is a huge challenge which in itself is like re-inventing the wheel of trial and error, when mathemati...
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Effect of Die Bearing Parameters on Corrosion Response of Extruded Al-Zn-Mg Alloy
Injor Oryina Mbaadega,
Adewuyi Benjamin Omotayo,
Gundu David Terfa
Issue:
Volume 4, Issue 3, May 2015
Pages:
209-212
Received:
5 May 2015
Accepted:
11 May 2015
Published:
27 May 2015
Abstract: In this paper, the effect of die bearing parameters (die bearing length and die reduction ratio) on corrosion response of extruded Al-Zn-Mg alloy was investigated. The alloy was target material for production of automobile bumper beams. Medium carbon steel dies with entry angles of 750, 900, 1050, 1200, 1500 and reduction ratios of 0.21, 0.40, 0.48 and 0.62 were used to extrude the alloy at temperature of 5000C. The extruded samples were subjected to electrochemical corrosion using Tafel polarization technique. The potential dynamic polarization curves indicated improvement in the corrosion resistance of the extruded alloy, and the corrosion rate under extruded condition increased with increase in both die angle and reduction ratio. It was concluded that the Al-Zn-Mg alloy is suitable for the target application.
Abstract: In this paper, the effect of die bearing parameters (die bearing length and die reduction ratio) on corrosion response of extruded Al-Zn-Mg alloy was investigated. The alloy was target material for production of automobile bumper beams. Medium carbon steel dies with entry angles of 750, 900, 1050, 1200, 1500 and reduction ratios of 0.21, 0.40, 0.48...
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The Role of Sulphate Reducing Bacteria in the Deterrioration of Oil Facilities; An Engineering Insight
Iweriolor Sunday,
Emereje Peter
Issue:
Volume 4, Issue 3, May 2015
Pages:
213-218
Received:
2 February 2015
Accepted:
29 April 2015
Published:
27 May 2015
Abstract: The paper describes an advanced approach in the analysis and control of corrosion resulting from the activities of sulphate reducing bacteria as well as the reacting species in the development of the biofilm. An anaerobic Cultured medium was prepared and the pH read on a scale was 7.4 and medium after incubation was dispensed into five anaerobic experimental pipe and the respective biocides (formaldehyde, polyamine, diamine, biguanide and cow urine) at different concentration ranging from 5 mg/l to 580 mg/l . Statistical procedures were also used to determine the correlation coefficient, coefficient of determination and polynomial equation generated on the basis of related information. The activities of the sulphate reducing bacteria results in the loss of weight of the coupons inserted and was found to be less in the experimental pipe with cow urine treatment.
Abstract: The paper describes an advanced approach in the analysis and control of corrosion resulting from the activities of sulphate reducing bacteria as well as the reacting species in the development of the biofilm. An anaerobic Cultured medium was prepared and the pH read on a scale was 7.4 and medium after incubation was dispensed into five anaerobic ex...
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Application of CaO from Psammotaea elongata Shell as Catalyst in Conversion the Beef Tallow to Biodiesel
I. Wayan Sutapa,
A. Bandjar,
Rosmawaty,
M. Sitaniapessy
Issue:
Volume 4, Issue 3, May 2015
Pages:
219-224
Received:
6 May 2015
Accepted:
18 May 2015
Published:
28 May 2015
Abstract: Synthesis of biodiesel from the beef tallow using catalyst from Psammotaea elongata shell with methanol as a solvent was carried out. Synthesis the biodiesel was prepared in two steps, there are esterification and transesterification. In esterification was conducted in mole ratio of oil and methanol were 1: 9, with H2SO4 as a catalyst. Transesterification process conducted with mole ratio were 1:12 (oil and methanol), with CaO from cockle’ shell as a catalyst with a variation of the catalyst 11%, 12%, 13%, and 14%. Result of biodiesel was characterized based on FT-IR, 1H-NMR, GC-MS, and ASTM (American Standard Testing of Materials) method. The results obtained by the catalyst conversion of 51.9% and the optimum conditions in the biodiesel present in 12%. Yielded of biodiesel theoretically was 59.118% and experiment was 18.34%. The main component on biodiesel product is methyl stearate (40.65%) and examination result of biodiesel by using ASTM method are specific (0.8695 g/cm3), kinematic viscosity (5.393 mm/s2), flame point (178.5 °C), pour point (24 °C), and carbon Condradson residue (0.071%).
Abstract: Synthesis of biodiesel from the beef tallow using catalyst from Psammotaea elongata shell with methanol as a solvent was carried out. Synthesis the biodiesel was prepared in two steps, there are esterification and transesterification. In esterification was conducted in mole ratio of oil and methanol were 1: 9, with H2SO4 as a catalyst. Transesterif...
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