Microstructural Evolution and Properties of Cu-1.5 Wt %Ti Alloy during Aging

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The microstructural evolution in Cu-1.5 wt % Ti alloy aged at 400 °C was investigated by high resolution electron microscopy (HREM). The hardness and electrical conductivity of this alloy have been also characterized. The electron metallographic results showed that the sequence of the decomposition in the studied Cu-1.5 wt % Ti alloy can be summarized as follows: a modulated structure resulting from spinodal clustering → formation of clusters and then ordered fcc phase → formation of LRO β’-Cu4Ti which distributed periodically along the <100>Cu directions. The ordered fcc phase showed a cube-on-cube OR with matrix, while the LRO β’-Cu4Ti showed an orientation relationship of [001]Cu//[001]β’ and (310)Cu//(100)β’. After aging for 24 h, the hardness and electrical conductivity of this alloy reached 175 HV and 25.3 % IACS, respectively. The spinodal clustering is responsible for the hardening of the alloy during the initial 30 min aging. The ordered fcc phase and β’-Cu4Ti phase makes a significant contribution to the strengthening of the alloy during the advanced stage of aging.

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183-193

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May 2020

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