Effect of initial microstructure on plastic flow behaviour during isothermal forging of Ti-10V-2Fe-3Al
Effect of initial microstructure on plastic flow behaviour during isothermal forging of Ti-10V-2Fe-3Al
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DOI：
10.1016/j.msea.2008.09.071
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发表时间：
2009-02-15
期刊：
影响因子：
6.4
通讯作者：
Dashwood, R. J.
中科院分区：
文献类型：
--
作者：
Jackson, M.;Jones, N. G.;Dashwood, R. J.
测定了近β合金Ti-10V-2Fe-3Al等温锻造过程中的塑性流动行为和组织演变。采用了两种不同的初始显微组织：(I)具有较大先前贝塔颗粒尺寸的贝塔锻坯和(Ii)具有先前球状初级α的α-贝塔锻坯。贝塔锻造状态显示出一个峰值应力，随后是强烈的流动软化，这归因于魏氏α血小板的破裂。有证据表明，低应变下的峰值硬化是由于α晶片/亚晶界面位错堆积所致，随后的流动软化是由于β相通过α晶片的传输。应变率“跳跃”试验表明，在高应变率下，Ti-10V-2Fe-3Al合金在锻造过程中存在由位错主导变形机制向低应变速率扩散主导变形机制的转变。(C)2008爱思唯尔B.V.保留所有权利。
The plastic flow behaviour and microstructural development during isothermal forging was determined for near beta alloy Ti-10V-2Fe-3Al. Two different initial microstructures were employed: (i) a beta forged billet with a large prior beta grain size with Widmanstatten alpha platelets; and (ii) an alpha-beta forged billet with prior globular primary alpha. The beta forged condition exhibited a peak stress followed by intense flow softening, which is attributed to the break up of the Widmanstatten alpha platelets. Evidence suggests that peak hardening at low strains is due to dislocation pile-ups at alpha platelet/subgrain beta interfaces and subsequent flow softening is attributed to the transmission of beta phase through the alpha platelets. A strain rate 'jump' test investigation provided sufficient evidence to suggest that there is a transition from dislocation dominant deformation mechanisms at high strains rates to diffusional dominant deformation at low strain rates in Ti-10V-2Fe-3Al during forging. (C) 2008 Elsevier B.V. All rights reserved.