TITANIUM ADDITION AND AGEING INFLUENCE ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Cu-10Ni ALLOY

Abstract

— The need to develop alloys with enhanced properties that will perform efficiently has continually become the major concern. In this study, the influence of Ti addition on the microstructure and mechanical properties of Cu-10Ni alloy was investigated. Cu-10Ni alloy was altered by adding Ti in the concentrations of 0.1, 0.2, 0.3, and 0.4wt%. The as-cast samples of Cu-10Ni alloy were solution treated at 900oC for 2 hr, quenched in water, and then aged at three different temperatures (400oC, 450oC and 500o ) for 2hr. Microstructural characteristics were observed using metallurgical microscope, and scanning electron microscope equipped with EDS, while tensile strength, hardness, impact strength and ductility as a function of mechanical properties were determined. Adding Ti contents in Cu-10Ni alloy and ageing at different temperatures greatly increased the properties and grain refinement of the alloy. The improvement in properties were due to slight promotion of precipitation and occurrence of enhanced TiNi3 particles after ageing treatment. The as-cast Cu-10Ni alloy had a peak value of 163MPa tensile strength, 127BHN hardness, and 142J impact strength at 0.1%Ti. Under the ageing condition, the samples with 0.4%Ti had peak tensile strength, hardness, and impact strength values of 574MPa, 193BHN, and 138j, respectively. The variation in the values of the tested properties of the alloys was measured on the role of the ageing temperature. The Ti addition promotes the growth of precipitates, which refines the microstructure during the ageing process and results in an excellent improvement of the properties of the Cu-Ni alloys.