dc.contributor.author | Gxowa, Zizo | |
dc.contributor.author | Chown, LH | |
dc.contributor.author | Govender, Sagren | |
dc.contributor.author | Curle, Ulyate | |
dc.date.accessioned | 2017-05-16T11:55:14Z | |
dc.date.available | 2017-05-16T11:55:14Z | |
dc.date.issued | 2016-10 | |
dc.identifier.citation | Gxowa, Z., Chown, L.H., Govender, G. et al. 2016. Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm). Journal of the Southern African Institute of Mining and Metallurgy, vol. 116(10): 963-968 | en_US |
dc.identifier.issn | 2225-6253 | |
dc.identifier.uri | http://saimm.org.za/Journal/v116n10p963.pdf | |
dc.identifier.uri | http://dx.doi.org/10.17159/2411-9717/2016/v116n10a11 | |
dc.identifier.uri | http://hdl.handle.net/10204/9052 | |
dc.description | Copyright: The authors 2016. | en_US |
dc.description.abstract | This work evaluates the deformation behaviour, at warm working temperatures, of green particle-reinforced aluminium composites produced by powder blending in a high-energy ball mill. The work focuses on metal matrix composites (MMCs) based on the 2124-Al alloy, reinforced with 10 or 15 vol.% SiC and metal matrix nanocomposites (MMNCs) based on the 2124-Al alloy, reinforced with 5 or 10 vol.% Al2O3. Three batches for each powder were blended and powder properties such as particle size distribution (PSD) and shape were consistent after blending. It was observed that a more uniform distribution of the reinforcement phase in the aluminium alloy matrix was achieved in 2124-Al/Al2O3 than in 2124-Al/SiC composites. The powders (unreinforced 2124-Al and blended) were initially over-aged at 350°C for 2 hours to reverse any natural ageing that may have occurred prior to use. The over-ageing was incorporated to improve compressibility of the powders with the aim of achieving green compacts with higher integrity. Uniaxial compression tests performed at ambient temperature on a Gleeble® 3500 thermomechanical simulator were unsuccessful as the green compacts fragmented. Engineering stress-strain curves showed that green compacts of unreinforced 2124-Al, 10%SiC MMC and 5%Al2O3 MMNC deformed in a similar manner at ambient temperature and had the same compressive fracture stress of approximately 170 MPa. When the deformation temperature was increased from ambient to warm working temperatures (170–280°C) it was observed that electrical resistance heating (the heating mode of the Gleeble®) of unreinforced Al alloy, MMC and MMNC green compacts did not occur. This was attributed to the high electrical conductivity of aluminium, which resulted in poor heat generation due to the low electrical resistance in the samples. It was presumed that the small sample size (d=8 mm, h=12 mm) also caused rapid heat loss. After further experimentation, the green compacts were heated successfully by insulating the samples to retain heat. It was found that at 280°C, increasing the soaking time from 6 to 20 minutes decreased flow stress and improved plastic flow in the 2124-Al/10%SiC green compact. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Southern African Institute of Mining and Metallurgy (SAIMM) | en_US |
dc.rights | CC0 1.0 Universal | * |
dc.rights.uri | http://creativecommons.org/publicdomain/zero/1.0/ | * |
dc.subject | Metal matrix composites | en_US |
dc.subject | Metal matrix nanocomposites | en_US |
dc.subject | 2124-Al alloy | en_US |
dc.title | Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm) | en_US |
dc.type | Article | en_US |
dc.identifier.apacitation | Gxowa, Z., Chown, L., Govender, S., & Curle, U. (2016). Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm). http://hdl.handle.net/10204/9052 | en_ZA |
dc.identifier.chicagocitation | Gxowa, Zizo, LH Chown, Sagren Govender, and Ulyate Curle "Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm)." (2016) http://hdl.handle.net/10204/9052 | en_ZA |
dc.identifier.vancouvercitation | Gxowa Z, Chown L, Govender S, Curle U. Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm). 2016; http://hdl.handle.net/10204/9052. | en_ZA |
dc.identifier.ris | TY - Article AU - Gxowa, Zizo AU - Chown, LH AU - Govender, Sagren AU - Curle, Ulyate AB - This work evaluates the deformation behaviour, at warm working temperatures, of green particle-reinforced aluminium composites produced by powder blending in a high-energy ball mill. The work focuses on metal matrix composites (MMCs) based on the 2124-Al alloy, reinforced with 10 or 15 vol.% SiC and metal matrix nanocomposites (MMNCs) based on the 2124-Al alloy, reinforced with 5 or 10 vol.% Al2O3. Three batches for each powder were blended and powder properties such as particle size distribution (PSD) and shape were consistent after blending. It was observed that a more uniform distribution of the reinforcement phase in the aluminium alloy matrix was achieved in 2124-Al/Al2O3 than in 2124-Al/SiC composites. The powders (unreinforced 2124-Al and blended) were initially over-aged at 350°C for 2 hours to reverse any natural ageing that may have occurred prior to use. The over-ageing was incorporated to improve compressibility of the powders with the aim of achieving green compacts with higher integrity. Uniaxial compression tests performed at ambient temperature on a Gleeble® 3500 thermomechanical simulator were unsuccessful as the green compacts fragmented. Engineering stress-strain curves showed that green compacts of unreinforced 2124-Al, 10%SiC MMC and 5%Al2O3 MMNC deformed in a similar manner at ambient temperature and had the same compressive fracture stress of approximately 170 MPa. When the deformation temperature was increased from ambient to warm working temperatures (170–280°C) it was observed that electrical resistance heating (the heating mode of the Gleeble®) of unreinforced Al alloy, MMC and MMNC green compacts did not occur. This was attributed to the high electrical conductivity of aluminium, which resulted in poor heat generation due to the low electrical resistance in the samples. It was presumed that the small sample size (d=8 mm, h=12 mm) also caused rapid heat loss. After further experimentation, the green compacts were heated successfully by insulating the samples to retain heat. It was found that at 280°C, increasing the soaking time from 6 to 20 minutes decreased flow stress and improved plastic flow in the 2124-Al/10%SiC green compact. DA - 2016-10 DB - ResearchSpace DO - 10.17159/2411-9717/2016/v116n10a11 DP - CSIR KW - Metal matrix composites KW - Metal matrix nanocomposites KW - 2124-Al alloy LK - https://researchspace.csir.co.za PY - 2016 SM - 2225-6253 T1 - Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm) TI - Deformation behaviour of aluminium low-micron MMCs and MMNCs at warm working temperatures (0.3—0.5 Tm) UR - http://hdl.handle.net/10204/9052 ER - | en_ZA |
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