Structure and corrosion endurance of dies from aluminum alloys

Dies produced from castable and deformable aluminum alloys are studied. The dies are used for molding articles from foaming plastics. Specimens for studying the microstructure are cut from the surface zone of dies. The stress state of the dies is determined by computation. The chemical composition of water and deposits on the surface of dies are studied in order to determine the causes of corrosion cracking. The effect of the composition of the alloy and of water on the composition of corrosion products deposited on die surfaces is studied by means of thermodynamic computation with the help of TERRA software. The materials of dies and alloys suitable for their production are studied and corrosion tests under actual operating conditions are performed. Anodized, epoxy, and epoxy-phenol coatings for the dies are tested. The causes of failure of aluminum dies are analyzed and recommendations for raising their endurance are given.