Respected Sir,

For compaction you can use cold isostatic pressing process (minimum 10 ton capacity hydraulic press) and dwell time will be 30 seconds. Usage of binder like polyvinyl alcohol or stearic acid is recommended. If no lubricant was mixed with the powder then you can use Acrawax C as a die wall lubricant to minimize friction and to ease ejection.

Thank You.

Dear sir,

Thanks for your valuable comments. Here I did not use any binder in the powder during my experiments. So, is it the reason for such a nonbonding appearance in the compacted sintered sample?

Kindly suggest the effect of the binder during compaction on the powder material. Does it change any mechanical properties of the final sample?

Please comment.

Binder has nothing to do with your problem. The main problem when sintering aluminum powder is oxidation. It is simply impossible to obtain oxide-free sintered aluminum alloy products using powder metallurgy. There is a material that is made from aluminum powder by sintering: SAP ( http://www.totalmateria.com/Article76.htm ), but this material has nothing to do with molten aluminum because it contains from 6 to 22% aluminum oxide. In addition, these sintered materials have to be sintered under pressure (hot pressing), because without pressure only very porous and weak sintered bodies are produced, as in your case.