dc.contributor.advisor | Holmestad, Randi | nb_NO |
dc.contributor.author | Martinsen, Fredrik Aleksander | nb_NO |
dc.date.accessioned | 2014-12-19T13:16:59Z | |
dc.date.available | 2014-12-19T13:16:59Z | |
dc.date.created | 2011-09-15 | nb_NO |
dc.date.issued | 2011 | nb_NO |
dc.identifier | 441335 | nb_NO |
dc.identifier | ntnudaim:6481 | nb_NO |
dc.identifier.uri | http://hdl.handle.net/11250/246506 | |
dc.description.abstract | The effect of clustering during natural aging of three different Al-Mg-Sialloys with equal Mg/Si-ratios, but different Mg+Si contents have beenstudied through hardness measurements and transmission electron mi-croscopy (TEM). Hardness measurements were performed both duringnatural aging (NA) and after various NA times followed by subsequentartificial aging for all alloys, while TEM-investigations were performedon selected samples. The results from the experiments were comparedand the existence of three different clustering processes were discovered.The first process was established to be Si-Si clustering causing a slighthardness increase during natural aging and a strong hardness increaseafter subsequent artificial aging. The second process was found to beMg-Mg clustering causing a significant hardness increase during naturalaging, and a clear decrease in hardness after subsequent artificial aging.The third process was found to be Mg-Si clustering and simultaneoustransformation of mono-clusters into co-clusters. This combined processcauses a hardness increase both during natural aging and after subse-quent artificial aging. The hardness increase is caused by a refinementof alloy microstructure including a higher number of smaller needles.This precipitate type was observed for all alloys and conditions. Thenegative effect of Mg-Mg clusters on precipitation hardness is suggestedto be related to the repulsion of Si from these clusters. This hinders theco-clustering of Mg and Si in the areas surrounding these clusters. | nb_NO |
dc.language | eng | nb_NO |
dc.publisher | Institutt for fysikk | nb_NO |
dc.subject | ntnudaim:6481 | no_NO |
dc.subject | MTFYMA fysikk og matematikk | no_NO |
dc.subject | Teknisk fysikk | no_NO |
dc.title | Clustering during Natural Aging and its Effect on Precipitation Hardening in Al-Mg-Si Alloys | nb_NO |
dc.type | Master thesis | nb_NO |
dc.source.pagenumber | 130 | nb_NO |
dc.contributor.department | Norges teknisk-naturvitenskapelige universitet, Fakultet for naturvitenskap og teknologi, Institutt for fysikk | nb_NO |