SOURCE:

Faculty: Engineering
Department: Metallurgical And Materials Engineering

CONTRIBUTORS:

Nwambu, C.N;
Nnuka, E.E;

ABSTRACT:

The improvement of performance of the structural sensitive properties of copper 10%aluminium alloy using carbide forming elements was studied in this research.A modification technique was used to improve the structure, mechanical and physical properties of copper-10%aluminium alloys. The elements used to modify the base alloy were titanium, zirconium, vanadium, manganese, chromium, molybdenum, tungsten and nickel at percentage weight composition of 0.5 to 10% wt at intervals of 0.5% wt. The base alloys were analysed using atomic absorption spectroscopy, structural analysis was conducted using optical metallurgical microscope, scanning electron microscope and energy dispersive spectroscopy.Mechanical properties such as ultimate tensile strength, yield strength, percentage elongation, impact strength and hardness were conducted.Digital hydraulic universal tensile testing machinewas used for ultimate tensile strength and yield strength.Impact testing machine was used for impact strength and portable dynamic hardness testing machine was used for hardness test.Design expert 10.0.6.software was utilized to design and develop mathematical models for the experiment.The structure showed that theβ phase transformed to theα +κ eutectoid and that the formation of (α+γ2) phase was suppressed. It also showed that the k-phase precipitated from the β phase.These led to improvement of the UTS by 52%, yield strength by 30%, hardness by 25% and resistivity by 39%. However, there were41.9% and 60% reductionof %E and impact strength respectively.The mathematical models developed will help to predict the effect of modifying elements and at any levels thereby reduce cost and time.The analysis of variance (ANOVA) shows that the modifying elements are significant factors that affected the experimental process. As a result of this improvement in structure andproperties of the developed alloys, they can be used for military application and in the aerospace industry.Secondly,those developed alloys modified with Ti, Zr, W, Mo and Cr should be used as a substitute for making component (propeller) in sea-going vessel as against alloys with Ni, Fe, Mg, Mn and V because of their high values of mechanical properties as obtained in this study.