Improvement of Al-6061 alloys mechanical properties by controlling processing parameters
— this paper discusses the effect of casting processing parameter on the mechanical properties of Aluminum alloy 6061 companied with Al 2 O 3 and Si C P. The specimens were poured in two different mold types one of steel and the other of graphite. These two types have a wide range of cooling rate; steel has fast cooling rate whereas graphite has slow one. In order to investigate this effect, and the alloying elements participation the specimens were taken from three different positions in the mold; top, middle and bottom. The mechanical wear, hardness and microstructure examination were performed. The results showed that wear rate and hardness increase in case of specimen poured in steel mold. This increasing due to fast cooling rate which make refining of the grain size of aluminum alloys. Whereas, their mechanical properties decreased when using graphite molds. In contrast of this result, ductility is increased. This is attributed to that graphite has slow cooling rate (heat dissipate is low) which make enlargement to the grain size of aluminum alloy and the graphite is also solid lubricate playing as interactive lubricate which is main reason to decrease the wear rate.
Mechanical properties of some PM aluminide and silicide reinforced 2124 aluminium matrix composites
Tensile properties of PM 2124 aluminium composites reinforced with Ni3Al, NiAl, Cr3Si and MoSi2 intermetallic powder particles have been investigated in tempering conditions T1 and T4. Intermetallics were produced by selfpropagated high-temperature synthesis and composite powders consolidated by extrusion. 2124/MoSi2 showed the highest thermal stability, and the best mechanical properties even after comparison with those of 2124/SiC composite after processing through the same route. 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Self-responsibility in health care/promotion: motivational factors.
This paper explores motivational factors at play in self-responsibility in health care and promotion. If people do not take responsibility for their health status, is it because they can not or will not? "Can" refers to the ability or skill to do something, while "will" refers to intention and effort. Each of these factors are analyzed in terms of their role as a cause of behavior in self-responsibility for the health status. Educational intervention to motivate self-responsibility is suggested as well as empirical research in how people attribute health outcomes.