INDUSTRIAL ENGINEERING

ASSIGNMENT

Research summary on Diecasting Die

 Submitted by

Ankit Sharma

Roll no.13

PGDIE 42

RESEARCH PAPER SOURCE

 Name - A. Kiełbus , T. Rzychoń , R. Cibis b

    University- a Silesian University of Technology,

             Address-   Krasińskiego 8, 40-019 Katowice, Poland

                  b NTP CIBIS Sp. z o.o.

                  Szkolna 15, 47-225 Kędzierzyn-Koźle, Poland

    Author e-mail address: andrzej.kielbus@polsl.pl

MICROSTRUCTURE OF AM50 DIE CASTING MAGNESIUM ALLOY

The maximum solubility of aluminium in magnesium at an eutectic temperature (437°C) is 14%, whereas an eutectic mixture occurs at 33% Al content. The content of aluminium in all industrial alloys of the AM series is not higher than the boundary solubility of Al in Mg. The equilibrium structure of these alloys is characterized by 100% presence of a solid solution, whereas the unbalanced structure, additionally metastable in casting alloys, shows the presence of an eutectic already at a 2% Al content.

 During die-casting solidification, the following sequence occurs. Primary solid solution a fine grains are nucleated at liquidus temperature. As the temperature is lowered, the time for diffusion is too short to allow equilibrium solidification. This caused a core structure, with an increasing concentration of aluminium towards grain boundaries. Next, along the grain boundaries, a divorced eutectic is hardness, and improves casting properties of an alloy. The best ratio of mechanical to plastic properties is obtained with a 6% Al content. Manganese does not cause any increase of tensile strength, however, it does slightly increase the yield point. It also brings about an increase of resistance to the action of sea water. The quantity of manganese in magnesium alloys is limited by its relatively low solubility in magnesium. Manganese content in alloys with an Al addition does not exceed 0.3% and 1.5% in alloys without Al addition. An addition of zinc in combination with Al aims at improving tensile strength at a room temperature; however 1% of Zn with a 7 to10% Al content in an alloy enhances hot cracking.

 The castability of magnesium alloys of the AM-series using the die-casting process is excellent. The good flow properties allow the casting of thin-walled parts and costs are reduces due to the fact that less material is needed. High pressure die casting is the dominant process for the mass production of magnesium components.