Kennedy J R, Rouat B, Daloz D, Bouzy E, Zollinger J
Department of Metallurgy & Materials Science and Engineering, Institut Jean Lamour, Université de Lorraine, Campus ARTEM, Allée André Guinier, F-54011 Nancy, France.
Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine, 57073 Metz, France.
Materials (Basel). 2018 Apr 25;11(5):666. doi: 10.3390/ma11050666.
The process of isomorphic inoculation relies on precise selection of inoculant alloys for a given system. Three alloys, Ti-10Al-25Nb, Ti-25Al-10Ta, and Ti-47Ta (at %) were selected as potential isomorphic inoculants for a Ti-46Al alloy. The binary Ti-Ta alloy selected was found to be ineffective as an inoculant due to its large density difference with the melt, causing the particles to settle. Both ternary alloys were successfully implemented as isomorphic inoculants that decreased the equiaxed grain size and increased the equiaxed fraction in their ingots. The degree of grain refinement obtained was found to be dependent on the number of particles introduced to the melt. Also, more new grains were formed than particles added to the melt. The grains/particle efficiency varied from greater than one to nearly twenty as the size of the particle increased. This is attributed to the breaking up of particles into smaller particles by dissolution in the melt. For a given particle size, Ti-Al-Ta and Ti-Al-Nb particles were found to have a roughly similar grain/particle efficiency.
同构孕育过程依赖于为特定体系精确选择孕育剂合金。选择了三种合金，Ti-10Al-25Nb、Ti-25Al-10Ta和Ti-47Ta（原子百分比）作为Ti-46Al合金的潜在同构孕育剂。所选的二元Ti-Ta合金由于其与熔体的密度差较大，导致颗粒沉降，被发现作为孕育剂无效。两种三元合金都成功用作同构孕育剂，减小了铸锭中等轴晶的尺寸并增加了等轴晶分数。发现获得的晶粒细化程度取决于引入熔体中的颗粒数量。此外，形成的新晶粒比添加到熔体中的颗粒更多。随着颗粒尺寸的增加，晶粒/颗粒效率从大于1变化到近20。这归因于颗粒在熔体中溶解而破碎成更小的颗粒。对于给定的颗粒尺寸发现，Ti-Al-Ta和Ti-Al-Nb颗粒具有大致相似的晶粒/颗粒效率。
