TEM Characterization and Properties of Cu-1 wt.% TiB2 Nanocomposite Prepared by Rapid Solidification and Subsequent Heat Treatment

Sobhani, M.; Arabi, H.; Mirhabibi, A. R.

doi:10.7508/jns.2012.04.016

TEM Characterization and Properties of Cu-1 wt.% TiB2 Nanocomposite Prepared by Rapid Solidification and Subsequent Heat Treatment

Document Type : Research Paper

Authors

M. Sobhani ¹

H. Arabi ²

A. R. Mirhabibi ³

¹ Center of Excellence for high strength alloys technology, School of Metallurgy and Materials Engineering, Iran

² University of Science and Technology, IUST, Tehran, 16845-118, Iran

³ Center of Excellence for Ceramic Materials in Energy and Environmental Applications, IUST, Tehran, Iran

10.7508/jns.2012.04.016

Abstract

Copper matrix composite reinforced by 1wt.% TiB2 particles was prepared using in situ reaction of Cu-1.4wt.% Ti and Cu-0.7wt.% B by rapid solidification and subsequent heat treatment for 1-20 hrs at 900ºC. High-resolution transmission electron microscopy (HRTEM) characterization showed that primary TiB2 particles were formed in liquid copper. Heat treatment of as-solidified samples led to the formation of secondary TiB2 particles via spinodal decomposition of titanium-rich zone inside the grains. Mechanical properties (after 50% reduction in area) as well as electrical conductivity of composite were evaluated after heat treatment and were compared with those of pure copper. The results indicated that, due to the formation of secondary TiB2 particles in the matrix, electrical conductivity increased along with hardness up to 10 hrs of heat treatment and reached 65% IACS and 155 HV, respectively. Moreover, the maximum ultimate (i.e. 580 MPa) and yield (i.e. 555 MPa) strengths of composite were achieved at this time.

Keywords

Copper composite

In situ reaction

Nano TiB2

Solidification

Spinodal