1) Aluminium alloy 
The Hiduminium alloys or R.R. alloys are a series of high-strength, high-temperature aluminium alloys, developed for aircraft use by Rolls-Royce before World War II. They were manufactured and later developed by High Duty Alloys Ltd.. The name Hi-Du-Minium is derived from that of High Duty Aluminium Alloys. The first of these Hiduminium alloys was...