Cast alloys for reciprocating engine heads-performance evaluation

Abstract

© 2018 IEEE. For the fabrication of reciprocating engine cylinder heads we touch upon relevant mechanical properties and comparisons between the use of two aluminium alloys-A: 9 % Si, 1 % Cu and B: 7 % Si, 3 % Cu. Manufacturing costs are reduced by means of a lowered Si content, particularly with respect to machining, but also this makes the material less dependent on those critical raw materials of importance to the European Union. Our study tests these mechanical properties: ultimate tensile strength, proof strength elongation and modulus of elasticity. It also carries out fatigue tests by the stair-case method. Microstructure is found to correlate to the mechanical properties. Even when tensile properties of alloy A are slightly higher, the fatigue performance at elevated temperatures makes alloy B more attractive for this application owing to: longer life expectancy of the part; lower machining costs; and lower quantities of the required critical raw material.