Effect Of Milling Time On Microstructure Of AA6061 Composites Fabricated Via Mechanical Alloying

Abstract

The aim of this work is to determine the effect of manufacturing conditions, especially milling time, on the microstructure and crystallite size of a newly developed nanostructural composite material with the aluminium alloy matrix reinforced with halloysite nanotubes. Halloysite, being a clayey mineral of volcanic origin, is characterized by high porosity and large specific surface area. Thus it can be used as an alternative reinforcement in metal matrix composite materials. In order to obtain this goal, composite powders with fine microstructures were fabricated using high-energy mechanical alloying, cold compacting and hot extrusion techniques. The obtained composite powders of aluminium alloy reinforced with 5, 10 and 15 wt% of halloysite nanotubes were characterized with SEM, TEM and XRD analysis. It has been proven that the use of mechanical alloying leads to a high degree of deformation, which, coupled with a decreased grain size below 100 nm and the dispersion of the refined reinforcing particles-reinforces the material very well.Keywords: aluminium matrix composites, halloysite nanotubes, mechanical milling, hot extrusion Celem niniejszej pracy było określenie wpływu warunków wytwarzania, w szczególności czasu mielenia, na strukturę i wielkość krystalitów nowo opracowanych nanostrukturalnych materiałów kompozytowych o osnowie stopów aluminium wzmacnianych nanorurkami haloizytowymi. Haloizyt, będący minerałem ilastym pochodzenia wulkanicznego, charakteryzuje się dużą porowatością, dużą powierzchnią właściwą, i może stanowić alternatywne wzmocnienie metalowych materiałów kompozytowych. W tym celu przy użyciu wysokoenergetycznego mechanicznego stopowania w młynie kulowym wytworzono rozdrobnione i trwale połączone proszki kompozytowe, które następnie poddano zagęszczaniu na zimno i wyciskaniu na gorąco. Tak opracowane materiały kompozytowe o udziale masowym haloizytowego wzmocnienia 5, 10, 15% zbadano metodami skaningowej i transmisyjnej mikroskopii elektronowej oraz rentgenowskiej analizy fazowej. Stwierdzono, że wywołane mechanicznym stopowaniem silne odkształcenie plastyczne i zmniejszenie rozmiaru ziarna poniżej 100 nm oraz dyspersja haloizytowych cząstek wzmacniających wpłynęła na znaczne umocnienie materiałów kompozytowych.

Effect of Milling Time on Microstructure and Properties of AA6061/MWCNTS Composite Powders / Wpływ Czasu Mielenia Na Strukturę I Własności Proszk Ów Kompozytowyc H AA6061/MWCNTS

“…But it has to be taking into account that other factors determining the powder flow rate are also particle size distribution, particle structure, particle surface, humidity, chemical composition and lubrication. The outcomes achieved confirm the information presented in the following works [16,17].…”

Composite Materials Infiltrated by Aluminium Alloys Based on Porous Skeletons from Alumina, Mullite and Titanium Produced by Powder Metallurgy Techniques

“…The technologies of their manufacturing processes are one of the most sharply evolving fields of materials engineering. In order to address the expectations of the market, it is substantiated to undertake measures aimed at developing alternative methods of light metal matrix composites, mainly aluminium and magnesium alloys [12][13][14][15][16][17][18][19][20][21][22]. Considering a high melting point, low density and good corrosion resistance of ceramics, the fibre-reinforced or particle-reinforced composites deriving from such ceramics are of special importance here.…”

Fabrication, Composition, Properties and Application of the AlMg1SiCu Aluminium Alloy Matrix Composite Materials Reinforced with Halloysite or Carbon Nanotubes

“…Both the uniform distribution of the reinforcing phase and its properties play an essential role in achieving improved material properties. One of the ways used for the uniform distribution of the reinforcing phase is to use mechanical synthesis methods, which have become one of the main ways to produce composite materials reinforced with carbon [55][56][57], and halloysite nanotubes [58,59]. The manufacturing of nanostructured composite materials with a matrix of aluminium alloys reinforced with carbon and halloysite nanotubes can be divided into two phases.…”