硕士学位毕业论文

硕士研究生：陈晓

指导教师：沈斌 教授 

答辩时间：2015.03

摘 要

镍基合金具有较高的蠕变强度、优越的抗腐蚀性能以及优良的耐磨性,因而能在高温下长时间工作,所以被广泛应用于航空、航天等领域的核心部件。纳米多孔材料具有例如低密度、较大内表面积和较高表面活性等优点。综合上述两个方面，镍基纳米多孔材料不仅具有镍基合金的优良性能，而且具有纳米多孔材料的特点。本文以得到镍基合金纳米膜的最优多孔性和最优渗入性为目标，研究纳米膜制备过程中的关键环节即筏化过程，对影响筏化过程的主要参数进行仿真优化研究。论文的主要内容包括：

1.  详细分析纳米膜的制备过程，通过对筏化过程的理论分析，分析产生材料多孔性和渗入性的原因以及影响得到材料多孔性和渗入性的因素，最终得出本文优化研究的具体对象，即辊压深度、辊轮半径以及加热温度等三个过程参数。

2.  应用有限元软件ABAQUS，建立辊压模型的有限元模型，分别在不同建模参数即网格尺寸、单元类型、质量缩放方法等的情况下进行镍合金板材筏化过程的有限元仿真，接着结合应力平衡理论公式及相关理论准则对仿真结果进行验证并从中选出最优的建模参数，从而使后续仿真结果可靠和准确。

3.  以优化选出的建模参数为基础，应用有限元软件ABAQUS，对影响筏化过程的基础参数即辊轮半径、辊压深度和加热温度进行多次仿真试验，统计比较结果，最终得出筏化过程的最优参数组合，使得板材经历筏化过程之后具有最大的多孔性区域和最大的平均渗入性区域，实现纳米膜的优化制备。最后提出进一步工作的方向。

关键词：辊压，筏化过程，有限元分析，纳米膜，镍基超级合金

ABSTRACT

Nickel-based alloy has high creep strength, good corrosion resistance and good wear resistance, which makes nickel-based alloy be able to work long time under high temperature, so nickel-based alloy is widely used in structures in aviation, aerospace and etc. Compared with other materials porous material has the advantage such as low density, large internal surface area and high surface activity. Nickel-based Nano porous material, which is a combination of nickel-based alloy and porous material, has also the combined advantages. The purpose of this thesis is to get the best porosity and the best penetration of nickel-based Nano-films, besides this thesis studies the rafting process, which is a key phase in the manufacture of Nano-films and this thesis simulates the main parameters affecting rafting process. The main content of this thesis is as follows:

1. Analyze the manufacture process of Nano-films, analyze the rafting process theoretically and analyze the reasons of the material porosity and penetration and the factors that influence the formation of porosity and penetration.

2. Utilize the FE-Software ABAQUS to establish a model of the rolling system, carry out the optimization process of modeling parameters and validate the optimization result according to theoretical formulations. The modeling parameters refer to the grid size, the element type and the mass scaling method.

3. Utilize the FE-Software ABAQUS to simulate the rafting process with different process parameters such as roller radius, the rolling depth and heating temperature, that influence the rafting process. Through the data statistics and comparison the optimal parameter group (roller radius, rolling depth and heating temperature) is finally obtained and the direction of further optimization is also proposed.

Key Words: cold rolling, rafting process, FEM, Nano-film, nickel-based super alloy