Solid-State Thermal Decomposition in a Cu-Rich Cu-Ti-Zr Alloy

TL;DR

This paper studies how a copper-rich alloy breaks down at high temperatures and identifies the phases formed during the process.

Contribution

The study introduces a new method to determine thermal decomposition pathways and phase diagrams in a single experimental cycle.

Findings

The decomposition pathway includes the (Cu) phase followed by Cu51Zr14 and Cu4Ti phases.

Solid solubility of Ti/Zr in the Cu matrix was observed between 820 °C and 801.5 °C.

First principle calculations evaluated the stability of Cu51Zr14 and Cu4Ti phases.

Abstract

Solid-state thermal decomposition in the Cu-13.3Ti-3.8Zr (at.%) alloy was studied using a synthesized method, including the temperature–concentration gradient and differential scanning calorimetry experiments within a single experimental cycle, as well as first principle calculations. Experimentally, the decomposition pathway and the solid solubility of Ti/Zr in the Cu matrix in the temperature range of 820 °C to 801.5 °C were observed in the Cu-13.3Ti-3.8Zr (at.%) alloy. The primary solid phase is (Cu) phase and subsequently precipitated Cu51Zr14 and Cu4Ti phases. These features are valuable for understanding the thermal stability and solid-state phase equilibria of the alloy. First principle calculations, including formation enthalpy, charge density, and electron localization function analyses, were conducted to evaluate the thermal, structural, and electrical stability of Cu51Zr14 with and without Ti doping, as well as Cu4Ti. The present work introduces an effective strategy for determining both the solid-state thermal decomposition pathway and the phase diagram within the solid-state region within a single experimental cycle.

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