CAJ | 학술논문

研究新型阻燃钛合金Ti14(α+Ti_2Cu)经不同变形量(45%～75%)半固态锻造后的热稳定性能,分析变形量对合金热稳定性能的影响.结果表明:变形量改变析出相的形态及晶粒尺寸,使合金具有不同的热稳定性能.随变形量的增加,Ti14合金热暴露后的强度呈先降低后升高的趋势,塑性有所改善.半固态变形量较小时(45%),合金晶粒粗大,Ti_2Cu相呈长条状分布于晶界,高的强度取决于析出相强化作用:随变形量增大(75%),晶粒细化,Ti_2Cu相呈颗粒状或短棒状弥散分布,产生细晶强化,使得强度和塑性都得到改善.断口分析表明:变形量较小,断口存在大量撕裂棱;变形量达到75%,断口以韧窝为主;表明析出相和晶粒尺寸共同决定Ti14合金的热稳定性能.
연구신형조연태합금Ti14(α+Ti_2Cu)경불동변형량(45%～75%)반고태단조후적열은정성능,분석변형량대합금열은정성능적영향.결과표명:변형량개변석출상적형태급정립척촌,사합금구유불동적열은정성능.수변형량적증가,Ti14합금열폭로후적강도정선강저후승고적추세,소성유소개선.반고태변형량교소시(45%),합금정립조대,Ti_2Cu상정장조상분포우정계,고적강도취결우석출상강화작용:수변형량증대(75%),정립세화,Ti_2Cu상정과립상혹단봉상미산분포,산생세정강화,사득강도화소성도득도개선.단구분석표명:변형량교소,단구존재대량시렬릉;변형량체도75%,단구이인와위주;표명석출상화정립척촌공동결정Ti14합금적열은정성능.
The thermal stability of Ti14, a novel α+Ti_2Cu burn resistant titanium alloy, after semi-solid forging (SSF) with different deformation amount from 45% to 75% was investigated. Effects of deformation amount on the thermal stability were analyzed. The results show that the deformation amount significantly affects the morphology of precipitates and grain size, leading to change of thermal stability. With the deformation amount increasing, the strength of Ti14 alloy after thermal exposure decreases first and then increases, and the plasticity was improved. When the deformation amount was 45%, the microstructure consisted of coarse grains and strip-like Ti_2Cu precipitates in the grain boundary. As deformation amount increases to 75%, the microstructure changed to refined grains and granular or/and short rod-like Ti_2Cu, inducing the improvement of strength and plasticity. Fracture analyses show that the fracture has lots of tearing ridges for small deformation amount; when the deformation amount reaches 75%, the fracture are mainly dimples. It indicates the precipitates and grain size determine the thermal stability of Ti14 alloy together.