Microstructural Modeling of Thermally-Driven β Grain Growth, Lamellae &Martensite in Ti-6Al-4V  

作　　者：Matteo Villa Jeffery W. Brooks Richard P. Turner Mark Ward Matteo Villa;Jeffery W. Brooks;Richard P. Turner;Mark Ward(School of Metallurgy & Materials, University of Birmingham, Birmingham, UK)

机构地区：[1]School of Metallurgy & Materials, University of Birmingham, Birmingham, UK

出　　处：《Modeling and Numerical Simulation of Material Science》2020年第3期55-73,共19页材料科学建模与数值模拟（英文）

摘　　要：The microstructural kinetics of <i>β</i> grain growth in the <i>β</i> field of a Ti-6Al-4V alloy was studied by a series of controlled heat treatments at constant temperature rates. Heating rates of 5<span style="white-space:nowrap;">°</span>C/s, 50<span style="white-space:nowrap;">°</span>C/s and 500<span style="white-space:nowrap;">°</span>C/s were considered, stopping at different peak temperatures. The thickness evolution of martensitic needles and lamellar <i>α</i> laths, formed on cooling, was also investigated, by soaking the material above its <i>β</i>-transus temperature and cooling down at 5<span style="white-space:nowrap;">°</span>C/s, 50<span style="white-space:nowrap;">°</span>C/s, 100<span style="white-space:nowrap;">°</span>C/s and 300<span style="white-space:nowrap;">°</span>C/s till ambient temperature. Quantitative microstructural analyses were used to measure the particle dimensions. The <i>β</i> grain growth kinetics was reasonably well described by a modified Avrami equation. The thickness of <i>α</i> lamellae was a function of the cooling rate and the <i>β</i> grain dimension in which they nucleated. The martensite needle thickness was shown to be a function of the cooling rate to which the material was subjected.The microstructural kinetics of <i>β</i> grain growth in the <i>β</i> field of a Ti-6Al-4V alloy was studied by a series of controlled heat treatments at constant temperature rates. Heating rates of 5<span style="white-space:nowrap;">°</span>C/s, 50<span style="white-space:nowrap;">°</span>C/s and 500<span style="white-space:nowrap;">°</span>C/s were considered, stopping at different peak temperatures. The thickness evolution of martensitic needles and lamellar <i>α</i> laths, formed on cooling, was also investigated, by soaking the material above its <i>β</i>-transus temperature and cooling down at 5<span style="white-space:nowrap;">°</span>C/s, 50<span style="white-space:nowrap;">°</span>C/s, 100<span style="white-space:nowrap;">°</span>C/s and 300<span style="white-space:nowrap;">°</span>C/s till ambient temperature. Quantitative microstructural analyses were used to measure the particle dimensions. The <i>β</i> grain growth kinetics was reasonably well described by a modified Avrami equation. The thickness of <i>α</i> lamellae was a function of the cooling rate and the <i>β</i> grain dimension in which they nucleated. The martensite needle thickness was shown to be a function of the cooling rate to which the material was subjected.

关 键 词：Titanium Welding Rapid Heating Phase Alpha BETA 

分 类 号：TG1[金属学及工艺—金属学]