In this research the effect of Nickel addition by various
percentages on the mechanical properties of
Aluminum-Copper alloy was studied. After
adding Nickel the alloys was artificially aged for different
times, and the effect of Nickel on
the re
sponse of alloy to precipitation hardening was studied.
Where the effect of Nickel on the microscope structure was
studied, and on the mechanical properties as hardness, tensile
strength, yield strength and elongation. The results showed that
the increase of Nickel improve this properties, where the highest
values were obtained when the Nickel's percentage was 5% Wt.
The effect of artificial aging on the revolution of mechanical
properties of aluminum alloy 6063-T5 has been studied. Samples of
aluminum profiles which are formed by extrusion process have
chosen, then studied the effect of artificial aging on th
e hardness
and mechanical properties by applied two aging stages and many
stages comparing to the traditional way which be done in one stage.
The aim of this work is to study the effect of the aging heat treatment on the pitting corrosion resistance of martensitic stainless steel. In this research a number of specimens from martensitic stainless steel were subjected to solution treatment a
t 1050 for one hour followed by water quenching then aging in the temperatures range (400-750) for different holding times (1-16 hrs).
After heat treatment, two types of corrosion tests (accelerated test and immersion test) were conducted. The results obtained in this research showed that the pitting corrosion resistance was
affected by Aging temperature and three critical temperatures were found in corrosion test: the
specimens aged at 475 0C had maximum corrosion rate. This may be due to the presence of stringer δ-
ferrite and precipitation of very fine precipitates which precipitated heterogeneously in the martensitic
matrix, which led to an increase in corrosion rate. The specimens aged at temperatures range (550 – 625) 0C had minimum values of corrosion rate, this is attributed to the high volume fraction of retained austenite. The specimens aged at temperatures above 625 had intermediate corrosion rate.
The type of pits, which resulted from two pitting corrosion tests, was independent form the form of δ-ferrite and carbides which presence in microstructure.
