镍铝合金微观弹性应力下有序沉淀相演变研究
摘要Ni3X型沉淀相是Ni 基合金主要的强化相，为面心立方结构呈有序排列，有序相的沉淀强化是Ni基合金的主要强化机制。因此，对于γ′相微观结构的控制成为发展Ni基高温合金的关键问题。本文基于微扩散方程和微观弹性力学理论，通过计算机模拟，来获得微观弹性应力、初始浓度对沉淀相的影响。随着铝浓度的上升，沉淀相的微观组织由低浓度时的大量的块状分布向高浓度时的大量长条状分布转变，且有较强的方向性，沿弹性应变能最小的方向[10]和[01]分布。而且铝浓度越高的时候，初始时序参数的起伏越大，达到平衡所需的时间越少，沉淀相只需很短时间即可完成有序化，并且成分达到平衡所需时间也越少，成分变化越快，平衡成分值与初始浓度无关。67164
毕业论文关键词 Ni-Al合金，沉淀相，弹性应力，微观组织
毕业设计说明书（论文）外文摘要
Title Microstructure Evolution of Ordered Phase Precipitation in Ni-Al Alloy with Elastic Strain
Abstract Ni3X type precipitates of Ni-base alloy main strengthening phase, face-centered cubic structure was ordered, is ordered phase precipitation hardening of Ni-base alloy main strengthening mechanisms. Therefore, the γ＇phase microstructure control as Ni-base superalloy development of the key issues.Based on micro-diffusion equation and microscopic theory of elasticity, through computer simulation, to obtain microscopic elastic stress, initial concentration of precipitates influence. With the increase in the concentration of aluminum, the microstructure of precipitates when the concentration by a low number of block distribution of the high concentration of large changes in the distribution strip, and has a strong directivity, the elastic strain energy along the direction of least [10] and [01] distribution. And the higher the concentration of aluminum when the ups and downs of the larger initial timing parameters, the time required to reach equilibrium fewer precipitates only a very short period of time to complete the ordering and the time required to reach equilibrium composition of the less composition changes faster, balance component value with the initial concentration.
Keywords ： Ni-Al alloy, precipitates, elastic stress, microstructure
目 次
1 绪论 1
1.1镍铝合金 1
1.1.1 概述 1
1.1.3 存在的问题 2
1.2 计算材料学 2
1.2.1 计算机在材料中的应用 2
1.2.2 微观组织演化的计算机模拟程序 2
2 相场模型 4
2.1相场基本方程 4
2.2 Ni-Al合金相场模型的建立 5
2.2.1 相场控制方程 5
2.2.2方程的数值解 9
2.2.3 Ni-Al合金物性参数 10
2.2.4 数值模拟过程 10
3 弹性应力下Ni-Al合金沉淀过程研究 12
3.1 不同浓度下Ni-Al合金微观结构演变 12
3.1.1 Ni-17.7%at.Al合金微观结构演变