Effects of additives on properties of Zr₅₀Al₁₅Ni₁₀Cu₂₅ amorphous powders in low-pressure sintering

¹ Department of Applied Physics, Hunan Agricultural University, Changsha 410128, P.R. China
e-mail: long-wy@hotmail.com
² School of Materials Science and Engineering, Central South University, Changsha 410083, P.R. China

Received: 5 July 2014
Accepted: 2 September 2015

Abstract

Amorphous Zr₅₀Al₁₅Ni₁₀Cu₂₅ powders were prepared by mechanical alloying technique from low-purity raw materials. The beneficial effects of a certain amount of external additives such as C, Si₃N₄ and SiC powders added to the amorphous powders on the thermal stability, densification and mechanical properties of the Zr₅₀Al₁₅Ni₁₀Cu₂₅ amorphous powders after low-pressure sintering were investigated. The blended powers were hand-pressed into bars in the air under 35 MPa pressure. The preformed bars were sintered in an argon atmosphere under low pressure. The samples were characterized by XRD, SEM, TEM, DSC and tensile testing. The results suggest that the crystallization process of Zr₅₀Al₁₅Ni₁₀Cu₂₅ during sintering could be inhibited for the increase in activation energy when the proper amount of external particles was added to the matrix. Furthermore, suitable additives could help to densify the matrix and improve its mechanical properties in the low-pressure sintering process.