β-CEZ钛合金在固溶时效时ω相与α相的组织演化规律

The Microstructure Evolution of ω and α Phase in the Solution Treatment and Ageing Process of β-CEZ Alloy

摘要:

本文主要通过SEM和TEM观察固溶时效过程β-CEZ钛合金ω相和α相的组织变化规律。发现β-CEZ合金在固溶处理后析出尺寸约1~2nm的无热ω相，在350℃～500℃时效处理时，ω相辅助形核析出长度约（100～200）nm的针状α相，且随着时效温度升高，α相数量增多，尺寸略有长大。当时效温度达到550℃时，ω相基本消失，α相继续长大到约300nm。当时效温度升高到650℃以后，晶界析出大量的长条状α相，晶内α相长度长大到数微米。

Abstract:

This article researched the microstructure evolution of ω and α phase in the solution treatment and ageing process of β-CEZ alloy, which is a kind of typical near-β titanium alloy. The results show that ultrafine athermal ω precipitates (about 1~2 nm) were formed in β-CEZ alloy by quenching from above the β transus temperature. Needle-like α precipitates, about 100nm in length, were formed when solution treated β-CEZ alloy samples were aged at 350℃. The scale of ω assisted α increased to about 200nm in length while increasing ageing temperature to 500℃. The scale of α precipitates grown to about 300nm in length and ω disappeared when the ageing temperature increased to 550℃. Long strip shape α were formed at grain boundaries and the scale of intragranular α increased to several microns when the β-CEZ alloy samples were aged above 650℃.