Effect of Shortened Heat Treatment on the Hardness and Microstructure of 320.0 Aluminium Alloy

Improvement of Al-Si alloys properties in scope of classic method is connected with change of Si preci pitations morphology through: using modification of the alloy, maintaining suitab le temperature of overheating and pouring process, as well as perfection of heat treatment methods. Growing requirements of the market make it necessary to search after such procedure s, which would quickly deliver positive results with simultaneous consideration of economic aspects. Presented in the paper shortened heat treatment with soaking of the alloy at temperature near temperature of solidus co uld be assumed as the method in the above mentioned understanding of the problem. Such treatment consists in soaking of the alloy to temperature of solutioning, keeping in such tempera ture, and next, quick quenching in water (20 0 C) followed by artificial ageing. Temperature ranges of solutioning and ageing treatments implemented i n the adopted testing plan were based on analysis of recorded curves from the ATD method. Obtained results relate to depende ncies and spatial diagrams describing effect of parameters of the solutioning and ageing treatments on HB hardness of the investig ated alloy and change of its microstructure. Performed shortened heat treatment results in precipitation hardening of the investiga ted 320.0 alloy, what according to expectations produces increased hardness of the mat erial.