Material characterization studies on the laser beam formed AISI 1008 mild steel
- Kumpaty, Subha, Brossard, Bradley, Kamara, Sheku, Akinlabi, Stephen A., Akinlabi, Esther Titilayo, Raju, Govinda, Panda, Nirmal, Balasubramanian, K.
- Authors: Kumpaty, Subha , Brossard, Bradley , Kamara, Sheku , Akinlabi, Stephen A. , Akinlabi, Esther Titilayo , Raju, Govinda , Panda, Nirmal , Balasubramanian, K.
- Date: 2014
- Subjects: Mechanical forming , Laser beam forming , Metal deformation
- Type: Article
- Identifier: uj:4743 , ISSN 978-93-81505-62-5 , http://hdl.handle.net/10210/11729
- Description: Laser Beam Forming is a new non-contact method without the use of a die, to achieve deformation in metals, which traditionally involved the application of mechanical forces to change the shape and form of the material permanently. Laser forming causes deformation by introducing thermal stresses from an external heat source as opposed to the simple application of forces in mechanical forming. In this study, samples were formed mechanically by using a dynamic press brake machine, whereby, a punch and die apply the force. A 4.4 kW Nd:YAG laser system was used to form a second set of samples made from cold rolled AISI 1008 mild steel using laser forming. In this collaborative work involving researchers from the USA, South Africa and India, the mechanical and metallurgical properties of the unformed, mechanically formed and laser formed samples were experimentally investigated. The objective is to compare these properties amongst the different samples in order to analyze the impact of the varying methodologies especially the laser energy effects on the samples. The conclusions from these tests have provided valuable information on the applicability of laser forming to attain the appropriate surface modifications yielding the desired mechanical and metallurgical properties of the metal.
- Full Text:
- Authors: Kumpaty, Subha , Brossard, Bradley , Kamara, Sheku , Akinlabi, Stephen A. , Akinlabi, Esther Titilayo , Raju, Govinda , Panda, Nirmal , Balasubramanian, K.
- Date: 2014
- Subjects: Mechanical forming , Laser beam forming , Metal deformation
- Type: Article
- Identifier: uj:4743 , ISSN 978-93-81505-62-5 , http://hdl.handle.net/10210/11729
- Description: Laser Beam Forming is a new non-contact method without the use of a die, to achieve deformation in metals, which traditionally involved the application of mechanical forces to change the shape and form of the material permanently. Laser forming causes deformation by introducing thermal stresses from an external heat source as opposed to the simple application of forces in mechanical forming. In this study, samples were formed mechanically by using a dynamic press brake machine, whereby, a punch and die apply the force. A 4.4 kW Nd:YAG laser system was used to form a second set of samples made from cold rolled AISI 1008 mild steel using laser forming. In this collaborative work involving researchers from the USA, South Africa and India, the mechanical and metallurgical properties of the unformed, mechanically formed and laser formed samples were experimentally investigated. The objective is to compare these properties amongst the different samples in order to analyze the impact of the varying methodologies especially the laser energy effects on the samples. The conclusions from these tests have provided valuable information on the applicability of laser forming to attain the appropriate surface modifications yielding the desired mechanical and metallurgical properties of the metal.
- Full Text:
Characterising the effect of springback on mechanically formed steel plates
- Akinlabi, Esther Titilayo, Matlou, Kagisho, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Matlou, Kagisho , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Mechanical forming , Springback
- Type: Article
- Identifier: uj:4724 , ISSN 2078-0958 , http://hdl.handle.net/10210/11549
- Description: In the bending operation, springback causes geometrical inaccuracies of bent parts. To curb springback, various factors such as bending parameters and material properties need to be considered. This paper reports the effects of springback on mechanically formed steel plates. Experimental work using circular bending was conducted to analyse the effect of springback on the formed steel sheets. The sheets were bent using a punch and die having a radius of curvature of 120 mm. In addition, the formed samples were characterized through microstructure, microhardness and tensile results. The results revealed an error due to springback of 4.24%. Furthermore, the Vickers microhardness of the formed samples compared to the parent materials shows an increase of 6% while the Ultimate Tensile Strength also increased by 7%. The effects of strain hardening resulting from the bending process led to the increased hardness and strength of the material. The formed samples had elongated grains when compared to the equiaxed grains of the parent material. The increase in the grains can be attributed to the stretching of the material during the bending process.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Matlou, Kagisho , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Mechanical forming , Springback
- Type: Article
- Identifier: uj:4724 , ISSN 2078-0958 , http://hdl.handle.net/10210/11549
- Description: In the bending operation, springback causes geometrical inaccuracies of bent parts. To curb springback, various factors such as bending parameters and material properties need to be considered. This paper reports the effects of springback on mechanically formed steel plates. Experimental work using circular bending was conducted to analyse the effect of springback on the formed steel sheets. The sheets were bent using a punch and die having a radius of curvature of 120 mm. In addition, the formed samples were characterized through microstructure, microhardness and tensile results. The results revealed an error due to springback of 4.24%. Furthermore, the Vickers microhardness of the formed samples compared to the parent materials shows an increase of 6% while the Ultimate Tensile Strength also increased by 7%. The effects of strain hardening resulting from the bending process led to the increased hardness and strength of the material. The formed samples had elongated grains when compared to the equiaxed grains of the parent material. The increase in the grains can be attributed to the stretching of the material during the bending process.
- Full Text:
Forming behaviour of steel sheets after mechanical and laser beam forming
- Akinlabi, Esther Titilayo, Shukla, M., Akinlabi, S. A., Kanyanga, S. B., Chizyuka, C. M.
- Authors: Akinlabi, Esther Titilayo , Shukla, M. , Akinlabi, S. A. , Kanyanga, S. B. , Chizyuka, C. M.
- Date: 2014
- Subjects: Laser beam forming , Mechanical forming , Microhardness , Microstructure , Tensile testing , Steel plates - Mechanical properties
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/379024 , uj:4998 , http://hdl.handle.net/10210/13136
- Description: This paper reports the influencing factors and the characteristic behaviour of steel plates during both the mechanical forming and laser beam forming processes. Samples of the steel sheets were mechanically bent to 120 mm curvatures using a 20 ton capacity eccentric mechanical press at room temperature and also with the laser beam using a 4.4 kW Nd: YAG laser system at a scan speed of 1.9 m/min, beam diameter of 12 mm, laser power of 1.7 kW at 25% beam overlap using argon for cooling the irradiated surfaces. The chemical composition of both the as-received material and the formed samples were analysed by emission spectroscopy to quantify the changes in the elemental composition. The result shows a percentage increase in the carbon after the mechanical and laser forming processes when compared to the parent material. This can be attributed to the enhancement resulting from the forming processes. The formed samples were further characterized through microstructure, microhardness and tensile tests. The microstructural characterisation of the samples revealed that the grains of the mechanically formed and laser formed components are elongated, it was also observed that there is an increase in the pearlite grains of the laser formed components resulting from the thermal heating during the laser process. The microhardness profiles of the formed components showed that there is a significant percentage increase in the Vickers microhardness values of the laser formed samples when compared to the mechanically formed samples and with respect to the parent material. The laser beam forming process can be considered a more appropriate forming process in terms of the resulting material properties in this regard.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Shukla, M. , Akinlabi, S. A. , Kanyanga, S. B. , Chizyuka, C. M.
- Date: 2014
- Subjects: Laser beam forming , Mechanical forming , Microhardness , Microstructure , Tensile testing , Steel plates - Mechanical properties
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/379024 , uj:4998 , http://hdl.handle.net/10210/13136
- Description: This paper reports the influencing factors and the characteristic behaviour of steel plates during both the mechanical forming and laser beam forming processes. Samples of the steel sheets were mechanically bent to 120 mm curvatures using a 20 ton capacity eccentric mechanical press at room temperature and also with the laser beam using a 4.4 kW Nd: YAG laser system at a scan speed of 1.9 m/min, beam diameter of 12 mm, laser power of 1.7 kW at 25% beam overlap using argon for cooling the irradiated surfaces. The chemical composition of both the as-received material and the formed samples were analysed by emission spectroscopy to quantify the changes in the elemental composition. The result shows a percentage increase in the carbon after the mechanical and laser forming processes when compared to the parent material. This can be attributed to the enhancement resulting from the forming processes. The formed samples were further characterized through microstructure, microhardness and tensile tests. The microstructural characterisation of the samples revealed that the grains of the mechanically formed and laser formed components are elongated, it was also observed that there is an increase in the pearlite grains of the laser formed components resulting from the thermal heating during the laser process. The microhardness profiles of the formed components showed that there is a significant percentage increase in the Vickers microhardness values of the laser formed samples when compared to the mechanically formed samples and with respect to the parent material. The laser beam forming process can be considered a more appropriate forming process in terms of the resulting material properties in this regard.
- Full Text:
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