Metallurgy

ABSTRACT Aluminum alloy 7075 has been widely studied, due to its excellent mechanical properties developed by age hardening and their extensive uses in the aircraft structure. Tensile test specimens were tested in various preaging conditions (100, 120, 140 degrees C) and various retrogression temperatures T(7) (160, 180, 200 degrees C) in order to evaluate the effect of heating cycles on the mechanical as well as corrosion properties. The optimum condition was preaging at T(6) 120 degrees C and retrogressing at T(7) 200 degrees C, which gave the highest hardness and tensile properties. The corrosion behavior of three-point-loaded specimens after 7 days of immersion in 3.5% NaCl solution, using modified electrochemical cell, was studied. The most resisting condition for SCC was preaging at T(6) = 100 degrees C and retrogression at T(7) = 160 degrees C for 250 min. Specimens retrogressed at 200 degrees C for 8 min showed low resistance to stress corrosion cracking.

The present investigation studies the processing of A356 Al-Si alloy containing up to 5% vol.-% nano-sized alo particles having size less than 500 nm. Composites were prepared using semi-solid casting route. To evaluate the results the alloys were further characterised by ...

Abstract: Specimens of precipitation hardening 16-5-1 stainless steel were solution treated at 1050 C for 1 h followed by aging at temperatures in the range 400–750 C for various holding times (1–16 h). After heat treatment, two types of corrosion test (accelerated and ...