Analysis and optimization of surface quality of stainless steel miniature gears manufactured by CO2 laser cutting
- Anghel, Cristina, Gupta, Kapil, Jen, T.C.
- Authors: Anghel, Cristina , Gupta, Kapil , Jen, T.C.
- Date: 2020
- Subjects: Gear , Laser , Machining
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/411159 , uj:34540 , Citation: Anghel, C., Gupta, K. & Jen. T.C. 2020. Analysis and optimization of surface quality of stainless steel miniature gears manufactured by CO2 laser cutting.
- Description: Abstract: This paper reports the results of investigation conducted on CO2 laser cutting of miniature gears of stainless steel 304. In this work, analysis of the effects of important laser parameters such as power, cutting speed, focal position, and gas pressure on average surface roughness (Ra) has been investigated. Stainless steel spur gears having 9.04 mm outside diameter and 4.5 mm face width have been cut using a CO2 laser system with nitrogen as assisted gas. A total of twenty nine experiments have been conducted based on BBD (Box-Behnken Design) technique of response surface methodology where aforementioned laser parameters varied at three levels each. ANOVA study found focal position as the most significant parameter. Further, the Desirability based optimization of laser parameters obtained best values of Ra- 0.43 µm at laser power- 2407 W, cutting speed- 1.25 m/min, focal position- (-) 2.4 mm, gas pressure- 12.5 bar. A scanned electron microscopy study also revealed the good surface morphology of the miniature gear machined at optimum parameters.
- Full Text:
- Authors: Anghel, Cristina , Gupta, Kapil , Jen, T.C.
- Date: 2020
- Subjects: Gear , Laser , Machining
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/411159 , uj:34540 , Citation: Anghel, C., Gupta, K. & Jen. T.C. 2020. Analysis and optimization of surface quality of stainless steel miniature gears manufactured by CO2 laser cutting.
- Description: Abstract: This paper reports the results of investigation conducted on CO2 laser cutting of miniature gears of stainless steel 304. In this work, analysis of the effects of important laser parameters such as power, cutting speed, focal position, and gas pressure on average surface roughness (Ra) has been investigated. Stainless steel spur gears having 9.04 mm outside diameter and 4.5 mm face width have been cut using a CO2 laser system with nitrogen as assisted gas. A total of twenty nine experiments have been conducted based on BBD (Box-Behnken Design) technique of response surface methodology where aforementioned laser parameters varied at three levels each. ANOVA study found focal position as the most significant parameter. Further, the Desirability based optimization of laser parameters obtained best values of Ra- 0.43 µm at laser power- 2407 W, cutting speed- 1.25 m/min, focal position- (-) 2.4 mm, gas pressure- 12.5 bar. A scanned electron microscopy study also revealed the good surface morphology of the miniature gear machined at optimum parameters.
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Corrosion resistance of heat treated Ti6Al4V in NaCl
- Omoniyi, P.O., Akinlabi, E.T., Mahamood, R.M., Jen, T.C.
- Authors: Omoniyi, P.O. , Akinlabi, E.T. , Mahamood, R.M. , Jen, T.C.
- Date: 2021
- Subjects: Corrosion , Heat treatment , Ti6Al4V
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/485969 , uj:44190 , DOI: 10.1016/j.cdc.2021.100780 , Citation: P.O. Omoniyi, E.T. Akinlabi, R.M. Mahamood, T.C. Jen, Corrosion resistance of heat treated Ti6Al4V in NaCl, Chemical Data Collections, Volume 36, 2021, https://doi.org/10.1016/j.cdc.2021.100780.
- Description: Abstract: Please refer to full text to view abstract.
- Full Text:
- Authors: Omoniyi, P.O. , Akinlabi, E.T. , Mahamood, R.M. , Jen, T.C.
- Date: 2021
- Subjects: Corrosion , Heat treatment , Ti6Al4V
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/485969 , uj:44190 , DOI: 10.1016/j.cdc.2021.100780 , Citation: P.O. Omoniyi, E.T. Akinlabi, R.M. Mahamood, T.C. Jen, Corrosion resistance of heat treated Ti6Al4V in NaCl, Chemical Data Collections, Volume 36, 2021, https://doi.org/10.1016/j.cdc.2021.100780.
- Description: Abstract: Please refer to full text to view abstract.
- Full Text:
Design and construction of a thermoacoustically driven thermoacoustic refrigerator
- Alcock, A.C., Tartibu, L.K., Jen, T.C.
- Authors: Alcock, A.C. , Tartibu, L.K. , Jen, T.C.
- Date: 2017
- Subjects: Design , Thermoacoustic refrigeration , TADTAR
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250780 , uj:26139 , Citation: Alcock, A.C., Tartibu, L.K. & Jen, T.C. 2017. Design and construction of a thermoacoustically driven thermoacoustic refrigerator.
- Description: Abstract: This work describes the design and construction of a standing wave Thermoacoustically Driven Thermoacoustic Refrigerator (TADTAR). The thermoacoustic cooler is proposed in this study as an alternative sustainable solution to current issues with vapor compression refrigerators, due to its environmentally friendlier attributes and its solar energy driven capabilities. However, one of the main hindrances to the expansion of this technology is its current lack of efficiency and performance closely related to the designing of the device. Hence, a model has been designed and constructed to perform an experimental investigation of the device’s performance at the University of Johannesburg. This model will mainly be used to investigate the dynamics of the TADTAR arrangement. The TADTAR consists of two thermoacoustic systems namely a thermoacoustic engine coupled to a thermoacoustic refrigerator. The thermoacoustic engine consists of a heat source and a cordierite honeycomb stack which converts heat into acoustic energy. The heat pumping takes place within a thermoacoustic refrigerator. Guidance on the material selection, constraints and calculation of the geometrical configuration describing the device constitute the main contribution of this work
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- Authors: Alcock, A.C. , Tartibu, L.K. , Jen, T.C.
- Date: 2017
- Subjects: Design , Thermoacoustic refrigeration , TADTAR
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250780 , uj:26139 , Citation: Alcock, A.C., Tartibu, L.K. & Jen, T.C. 2017. Design and construction of a thermoacoustically driven thermoacoustic refrigerator.
- Description: Abstract: This work describes the design and construction of a standing wave Thermoacoustically Driven Thermoacoustic Refrigerator (TADTAR). The thermoacoustic cooler is proposed in this study as an alternative sustainable solution to current issues with vapor compression refrigerators, due to its environmentally friendlier attributes and its solar energy driven capabilities. However, one of the main hindrances to the expansion of this technology is its current lack of efficiency and performance closely related to the designing of the device. Hence, a model has been designed and constructed to perform an experimental investigation of the device’s performance at the University of Johannesburg. This model will mainly be used to investigate the dynamics of the TADTAR arrangement. The TADTAR consists of two thermoacoustic systems namely a thermoacoustic engine coupled to a thermoacoustic refrigerator. The thermoacoustic engine consists of a heat source and a cordierite honeycomb stack which converts heat into acoustic energy. The heat pumping takes place within a thermoacoustic refrigerator. Guidance on the material selection, constraints and calculation of the geometrical configuration describing the device constitute the main contribution of this work
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Effect of weight per meter of reinforced bar on mechanical properties and microstructure
- Musonda, V., Akinlabi, Esther Titilayo, Jen, T.C.
- Authors: Musonda, V. , Akinlabi, Esther Titilayo , Jen, T.C.
- Date: 2017
- Subjects: Billets , Hot rolling , Microstructure
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/241963 , uj:24945 , Citation: Musonda, V., Akinlabi, E.T. & Jen, T.C. 2017. Effect of weight per meter of reinforced bar on mechanical properties and microstructure.
- Description: Abstract: Reinforced bars (rebars) are Thermo-mechanically treated (TMT) bars hot rolled from steel billets produced from scrap melted in an Electric Arc Furnace (EAF) at a temperature of about 1600 ℃ (usually 1580℃). Weight per meter of a low carbon steel rebar is one aspect which has been neglected by some steel producers during the tensile testing in the rod mill. Determination of weight per metre is explicitly required for a TMT rebar. Any reduction in mass will mean a lowering in capacity of the steel reinforcing bar. A series of “heat” numbers or batches of molten steel from an EAF for the production of steel sample A, (Y10 and Y 12 rebars), were observed at a Steel plant to investigate the effect of weight per meter of reinforced bar on the mechanical properties and microstructure. The rolling speed range was 3m/s to 14 m/s for different “heats”. Two other steel samples B and C were sourced from the local market to compare with Sample A. Samples collected from different sources on the local market, however, showed lower values of weight per meter different from the prescribed standards. This did not only affect the ultimate tensile strengths which were higher than normal but also the microstructure which deviated from the standard for this material. Sample A, did not only show a good combination of tensile strength and yield stress of 450MPa and a maximum tensile strength of 650MPa but also a standard pearliteferrite microstructure, while sample B and C exhibited excessive high strengths and brittle behaviour and can be prone to failure.
- Full Text:
- Authors: Musonda, V. , Akinlabi, Esther Titilayo , Jen, T.C.
- Date: 2017
- Subjects: Billets , Hot rolling , Microstructure
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/241963 , uj:24945 , Citation: Musonda, V., Akinlabi, E.T. & Jen, T.C. 2017. Effect of weight per meter of reinforced bar on mechanical properties and microstructure.
- Description: Abstract: Reinforced bars (rebars) are Thermo-mechanically treated (TMT) bars hot rolled from steel billets produced from scrap melted in an Electric Arc Furnace (EAF) at a temperature of about 1600 ℃ (usually 1580℃). Weight per meter of a low carbon steel rebar is one aspect which has been neglected by some steel producers during the tensile testing in the rod mill. Determination of weight per metre is explicitly required for a TMT rebar. Any reduction in mass will mean a lowering in capacity of the steel reinforcing bar. A series of “heat” numbers or batches of molten steel from an EAF for the production of steel sample A, (Y10 and Y 12 rebars), were observed at a Steel plant to investigate the effect of weight per meter of reinforced bar on the mechanical properties and microstructure. The rolling speed range was 3m/s to 14 m/s for different “heats”. Two other steel samples B and C were sourced from the local market to compare with Sample A. Samples collected from different sources on the local market, however, showed lower values of weight per meter different from the prescribed standards. This did not only affect the ultimate tensile strengths which were higher than normal but also the microstructure which deviated from the standard for this material. Sample A, did not only show a good combination of tensile strength and yield stress of 450MPa and a maximum tensile strength of 650MPa but also a standard pearliteferrite microstructure, while sample B and C exhibited excessive high strengths and brittle behaviour and can be prone to failure.
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Optimum temperature of hot rolled reinforced bars at the cooling bed
- Musonda, V., Akinlabi, Esther Titilayo, Jen, T.C.
- Authors: Musonda, V. , Akinlabi, Esther Titilayo , Jen, T.C.
- Date: 2017
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/241955 , uj:24944 , Citation: V Musonda et al 2017 IOP Conf. Ser.: Mater. Sci. Eng. 225 012297
- Description: Abstract: Maintaining high accuracy temperature measurements at the cooling section is essential in order to attain the overall quality of the finished product, and to realise the correct properties. A series of “heat” numbers or batches of molten steel from an Electric Arc Furnace (EAF) for the production of Y12 mm reinforced bars (rebars) were observed at a steel plant to establish the optimum temperature of the rebar at the cooling bed. The casting was done in billet casters and the billets with 100mm×100mm cross-section were then hot rolledto the required size. The finish rolling temperature was between 850-900℃ at 11m/s rolling speed. Therebars were water quenched in the water box, and lastlysent for cooling on the cooling bed. Tensile tests and bend tests were carried out on rebars every after 15 minutes during the production to ensure that correct mechanical properties were achieved. It was observed that 850℃ was the bestfinishing temperature and 250 ℃ was the optimum temperature at the cooling bed after equalization.Theresults for the tensile tests and microstructures wereconsistent with prescribed standards. The rebar samples were all of low carbon steel.
- Full Text:
- Authors: Musonda, V. , Akinlabi, Esther Titilayo , Jen, T.C.
- Date: 2017
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/241955 , uj:24944 , Citation: V Musonda et al 2017 IOP Conf. Ser.: Mater. Sci. Eng. 225 012297
- Description: Abstract: Maintaining high accuracy temperature measurements at the cooling section is essential in order to attain the overall quality of the finished product, and to realise the correct properties. A series of “heat” numbers or batches of molten steel from an Electric Arc Furnace (EAF) for the production of Y12 mm reinforced bars (rebars) were observed at a steel plant to establish the optimum temperature of the rebar at the cooling bed. The casting was done in billet casters and the billets with 100mm×100mm cross-section were then hot rolledto the required size. The finish rolling temperature was between 850-900℃ at 11m/s rolling speed. Therebars were water quenched in the water box, and lastlysent for cooling on the cooling bed. Tensile tests and bend tests were carried out on rebars every after 15 minutes during the production to ensure that correct mechanical properties were achieved. It was observed that 850℃ was the bestfinishing temperature and 250 ℃ was the optimum temperature at the cooling bed after equalization.Theresults for the tensile tests and microstructures wereconsistent with prescribed standards. The rebar samples were all of low carbon steel.
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