Surface morphology is a significant aspect of a solid material, whether for aesthetic or function... more Surface morphology is a significant aspect of a solid material, whether for aesthetic or functional purposes and currently, through different surface modification methods, developments have been dedicated into advancing metallic materials to improved surface characteristics. Additively manufactured aluminium alloys have demonstrated an extensive choice of appropriate characteristics for different uses desired for the aviation and space industry. However, the surface hardness and tribological properties are insufficient in these materials due to the fact that when one property is enhanced one is compromised especially after thermal treatment. This makes the significant development and modification of the surface properties very imperative for existing and forthcoming engineering applications. There are many types of surface modification techniques used, in this paper an optimization of the barrel finishing that uses ceramic polishing media for commercially build SLM produced AlSi10Mg...
IOP Conference Series: Materials Science and Engineering, 2019
The AlSi10Mg alloy is known for its castability, corrosion resistance, high heat conductivity, lo... more The AlSi10Mg alloy is known for its castability, corrosion resistance, high heat conductivity, low weight and good weldability. Applications of the aluminium alloy components includes heat exchangers that are subjected to high temperatures and corrosive environments. The production process of AlSi10Mg alloy using selective laser melting has been extensively explored because of its hypoeutectic composition of Al and Si. However, it has been observed that stress relieve has a negative consequence on tensile properties of SLM built samples, while retaining and improving ductility. The thermal behaviour of AlSi10Mg alloy fabricated by selective laser melting with the specimen heat treated at 300°C for 2 hours investigated in this work. The specimens exhibited mass gain during the thermalgravimetric analysis as a result of the precence of oxygen as one of the elements present as detected by the elemental analysis. The fatigue results post thermal treatment demonstrated improved fatigue r...
The heating and cooling profiles experienced during laser additive manufacturing results in resid... more The heating and cooling profiles experienced during laser additive manufacturing results in residual stresses build up in the component. Therefore, it is necessary to perform post build stress relieving towards the retention and improvement of the mechanical properties. However the thermal treatments for conventional manufacturing do not seem to completely accommodate these rapid heating and cooling cycles of laser processing techniques such as powder bed fusion. Characterizations such as density measurements on the samples were performed employing the Archimedes principle; hardness testing was performed on the Zwick micro/macro (Hv) hardness tester, SEM and Electron backscatter diffraction (EBSD). Fracture toughness and crack growth was conducted on a fatigue crack machine. All characterization was done after stress relieving of Selective Laser Melting (SLM) produced samples at 300 °C for 2 hrs was performed in a furnace. The mechanical properties appear to be rather compromised in...
This article reports on an exceptional insight provided by nondestructive X-ray tomography of the... more This article reports on an exceptional insight provided by nondestructive X-ray tomography of the same samples before and after laser shock peening (LSP). The porosity in two additively ma...
Additive manufacturing is currently applied across a broad material selection and it is growing i... more Additive manufacturing is currently applied across a broad material selection and it is growing in production volume and economic impact. Aluminium is one of the materials that play a significant role in the aerospace industry because of its good strength-to-weight ratio. However, comparatively lower interest is shown in the additive manufacturing of aluminium alloys compared to titanium alloys, therefore there is much scope for data gathering and development of this material. In this investigation, the microstructure and mechanical properties of AlSi10Mg that were built using selective laser melting at different orientations are explored. The specimen were built in the XY, 45° and Z orientations. The microstructures of the obtained samples showed typical scan patterns with the density and hardness values similar to literature values. The XY built samples showed the lowest level of porosity and also possessed the lowest ultimate tensile strength and elongation. In contrast, the 45° ...
Surface morphology is a significant aspect of a solid material, whether for aesthetic or function... more Surface morphology is a significant aspect of a solid material, whether for aesthetic or functional purposes and currently, through different surface modification methods, developments have been dedicated into advancing metallic materials to improved surface characteristics. Additively manufactured aluminium alloys have demonstrated an extensive choice of appropriate characteristics for different uses desired for the aviation and space industry. However, the surface hardness and tribological properties are insufficient in these materials due to the fact that when one property is enhanced one is compromised especially after thermal treatment. This makes the significant development and modification of the surface properties very imperative for existing and forthcoming engineering applications. There are many types of surface modification techniques used, in this paper an optimization of the barrel finishing that uses ceramic polishing media for commercially build SLM produced AlSi10Mg...
IOP Conference Series: Materials Science and Engineering, 2019
The AlSi10Mg alloy is known for its castability, corrosion resistance, high heat conductivity, lo... more The AlSi10Mg alloy is known for its castability, corrosion resistance, high heat conductivity, low weight and good weldability. Applications of the aluminium alloy components includes heat exchangers that are subjected to high temperatures and corrosive environments. The production process of AlSi10Mg alloy using selective laser melting has been extensively explored because of its hypoeutectic composition of Al and Si. However, it has been observed that stress relieve has a negative consequence on tensile properties of SLM built samples, while retaining and improving ductility. The thermal behaviour of AlSi10Mg alloy fabricated by selective laser melting with the specimen heat treated at 300°C for 2 hours investigated in this work. The specimens exhibited mass gain during the thermalgravimetric analysis as a result of the precence of oxygen as one of the elements present as detected by the elemental analysis. The fatigue results post thermal treatment demonstrated improved fatigue r...
The heating and cooling profiles experienced during laser additive manufacturing results in resid... more The heating and cooling profiles experienced during laser additive manufacturing results in residual stresses build up in the component. Therefore, it is necessary to perform post build stress relieving towards the retention and improvement of the mechanical properties. However the thermal treatments for conventional manufacturing do not seem to completely accommodate these rapid heating and cooling cycles of laser processing techniques such as powder bed fusion. Characterizations such as density measurements on the samples were performed employing the Archimedes principle; hardness testing was performed on the Zwick micro/macro (Hv) hardness tester, SEM and Electron backscatter diffraction (EBSD). Fracture toughness and crack growth was conducted on a fatigue crack machine. All characterization was done after stress relieving of Selective Laser Melting (SLM) produced samples at 300 °C for 2 hrs was performed in a furnace. The mechanical properties appear to be rather compromised in...
This article reports on an exceptional insight provided by nondestructive X-ray tomography of the... more This article reports on an exceptional insight provided by nondestructive X-ray tomography of the same samples before and after laser shock peening (LSP). The porosity in two additively ma...
Additive manufacturing is currently applied across a broad material selection and it is growing i... more Additive manufacturing is currently applied across a broad material selection and it is growing in production volume and economic impact. Aluminium is one of the materials that play a significant role in the aerospace industry because of its good strength-to-weight ratio. However, comparatively lower interest is shown in the additive manufacturing of aluminium alloys compared to titanium alloys, therefore there is much scope for data gathering and development of this material. In this investigation, the microstructure and mechanical properties of AlSi10Mg that were built using selective laser melting at different orientations are explored. The specimen were built in the XY, 45° and Z orientations. The microstructures of the obtained samples showed typical scan patterns with the density and hardness values similar to literature values. The XY built samples showed the lowest level of porosity and also possessed the lowest ultimate tensile strength and elongation. In contrast, the 45° ...
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