【作者】 刘颖峰；

【导师】 廖世杰；

【作者基本信息】 湘潭大学 ， 材料加工工程， 2004， 硕士

【摘要】 织构在传统的基础上，经过多年的发展已成为一门新兴发展的科学而受到了人们广泛的关注。广义的说，某种具有择优取向的结构称为织构。其特点之一是晶粒的微观取向可以在宏观某方向上得到表现，故显示了微观取向和宏观某方向的统一，可以体现出各种宏观性能的各向异性。大多数的金属材料都存在这种现象，这就使得织构的研究加倍重要。大量的实验和理论的创新丰富了这门科学的内容，并进一步推动了与之相关联的其他学科的发展，从而使这门学科所涵盖的知识面更加广博，因此随着织构这一科学的不断完善发展，也就出现了不同的分支。定向凝固织构就是其中的一种很具代表意义的分支。它主要是通过定向凝固的手段，使金属或合金生长出某一特定织构，从而满足性能在某个方向的择优的要求。国内外许多研究人员已经做了许多相关实验，通过改变实验条件而改变织构的方向，并且发现了不同结构的金属或合金能产生的不同织构。但是，到底是什么因素影响织构的生长呢？织构生长的机理是什么呢？在这方面至今还没什么进展，因而机理的提出对于定向凝固织构方面的工作就显得尤为重要。本人在硕士阶段通过对面心立方，体心立方，密排六方和菱方结构四种具有不同结构和对称性的织构的研究，并做出了面心立方，密排六方和菱方结构的金属或合金的定向凝固样品，对他们进行了极图，反极图和ODF定量分析，得出了它们的织构，然后从结晶学的角度考虑晶体生长习性，提出了不同晶体结构的定向凝固织构的生长机理。这一机理可以很好解释并预测单一温度场条件下的各种结构的定向凝固织构。虽然这一机理还不够完善，但是，相信在以后的研究中，如果考虑到更多的影响因素，有更多的不同条件下的实验数据的支持，一定可以提出更加完善的机理。更多还原

【Abstract】 Texture，as a newly developed subject, attracts much public attention. Because texture is a kind of uniform between the micro-orientation of crystalline grains and a certain macro-direction, it exhibits anisotropy of all kinds of macro-properties which is a universe phenomenon in all materials that makes the study of texture double important. Plenty of innovation of experiments and theories enriches the subject and improves the development of related study. More knowledge is involved in the subject , therefore, with the development and improvement of which, different branches appear.Directional solidification texture is one representative part of texture study. It can make the metals or alloys form a certain texture by directional solidification which can satisfy the best property requirements along one direction. Many researchers have conducted a lot of relative experiments which reveal that different metals and alloys with different structures can produce different texture on different conditions.However, what on earth affects the growth of texture? And what’s the mechanism? There were few developments in this field, because of which, it was putting forward a proper mechanism that became especially important for the study of directional solidification texture. Based on the research of four kinds of different texture of fcc, bcc, hcp and rhombohedra structure, the author successfully finished the specimen preparation of metals and alloys with the structure of fcc, hcp, and rhombohedra. Furthermore, the texture was quantitatively analyzed by pole figure，inverse pole figure and ODF. Once the directional solidification texture is confirmed, a new mechanism will be put forward which involves the crystallization habit of different crystal face. Although the mechanism is not perfect, it can explain and anticipate the directional solidification texture of different structures <WP=5>on the condition of single temperature field. If more affecting factors are thought together, and the texture analysis is supported by more experiment data, a more perfect mechanism will come out.更多还原