离心烧结工艺制备氧化铝陶瓷毕业论文
2021-11-21 16:17:46
论文总字数:18540字
摘 要
氧化铝陶瓷具有强度高、耐高温、耐腐蚀、耐磨损及良好的介电性能等特性,在电子、冶金、机械、交通、能源、航空航天和生物领域得到广泛的应用[[1]]。如何设计出有用的金属颗粒增强Al2O3陶瓷基复合梯度材料的制备工艺,得到能满足实际应用需要的梯度材料,成为目前材料研究领域的重点。但是,梯度材料各层由于组分差异会导致最佳烧结温度差异,不易整体一次烧结;同时当前对于复杂形状的梯度材料制备也比较困难。本文采用离心烧结的方法制备Al2O3/Ni功能梯度材料,研究了工艺参数对Al2O3/Ni复合浆料流变性能的影响,并对制得材料进行性能测试。
通过改变Al2O3/Ni复合浆料的流变性能,可以控制不同原料颗粒在离心过程中因为密度和颗粒尺寸的不同而分离的速度,从而得到符合预期梯度分布的材料。研究发现,通过调节复合浆料的分散剂种类及添加量以及粘结剂含量,可有效改变浆料的流动特性,从而调节离心喷涂梯度层的成型效果;并确定出与研制设备相配套的最佳工艺条件,在此工艺条件下,浆料可以均匀喷涂到管状基体上,保持设计组分梯度。
在 1400 ℃下烧结制备了管状 Al2O3/Ni 梯度材料,整体致密度较高,并对材料进行了表征和力学性能测试。上述工作为致密、管状梯度材料的制备提供了一种有效的技术途径。
关键词:Al2O3/Ni;陶瓷材料;复合材料;梯度功能材料;离心成型
Abstract
Alumina ceramics have the characteristics of high strength, high temperature resistance, corrosion resistance, wear resistance and good dielectric properties, and are widely used in the fields of electronics, metallurgy, machinery, transportation, energy, aerospace and biology.How to design a useful metal particle reinforced Al2O3 ceramic matrix composite gradient material preparation process to obtain a gradient material that can meet the needs of practical applications has become the focus of the current material research field. However, due to the difference in composition of the layers of the gradient material, the optimal sintering temperature difference is not easy to sinter as a whole; at the same time, the preparation of gradient materials with complex shapes is also difficult at present.In this paper, Al2O3/Ni functionally graded materials were prepared by centrifugal sintering. The effect of process parameters on the rheological properties of Al2O3/Ni composite slurry was studied, and the properties of the prepared materials were tested.
By adjusting the rheological properties of the Al2O3/Ni composite slurry, the speed of separation of different raw material particles during centrifugation due to the difference in density and particle size can be controlled, thereby obtaining materials that meet the expected gradient distribution. The study found that by adjusting the type and amount of the dispersant of the composite slurry and the content of the binder, the flow characteristics of the slurry can be effectively changed, thereby adjusting the molding effect of the gradient layer of the centrifugal spray; and determining the best matching with the development equipment Excellent process conditions. Under this process condition, the slurry can be evenly sprayed onto the tubular substrate to maintain the design composition gradient.
The tubular Al2O3/Ni gradient material was prepared by sintering at 1400 ℃. The overall density was higher, and the material was characterized and tested for mechanical properties. The above work provides an effective technical approach for the preparation of dense, tubular gradient materials.
Key Words:Al2O3/Ni;Ceramic material;Composite materials; gradient functional materials; centrifugal forming
目 录
第1章 绪论 1
1.1功能梯度材料 1
1.1.1功能梯度材料的应用 1
1.1.2功能梯度材料的研究现状 2
1.1.3功能梯度材料的发展前景 6
1.2 Al2O3/Ni梯度材料的研究现状 6
1.3离心成型研究现状 7
1.4本文研究目的及主要内容 8
第2章 原材料与实验方法 9
2.1实验试剂及材料 9
2.2材料制备方法及设备 9
2.3材料制备工艺流程 10
2.4性能测试与结构分析 11
2.4.1材料分析 11
2.4.2材料性能测试 11
第3章 Al2O3/Ni梯度材料的制备及性能研究 14
3.1均匀Al2O3/Ni复合浆料的制备 14
3.1.1分散剂对浆料流变特性的影响 14
3.1.2粘结剂对浆料流变特性的影响 15
3.2 Al2O3/Ni复合浆料的离心成型 15
3.3 Al2O3/Ni梯度材料的烧结 15
3.4 Al2O3/Ni梯度材料的性能测试 16
第4章 结论与展望 18
4.1结论 18
4.2展望 18
致 谢 19
参考文献 20
附 录 22
第1章 绪论
1.1功能梯度材料
随着科学技术的不断进步,人们对材料在各种极端环境下的使用要求不断提高,传统的陶瓷、金属以及复合材料已经不能满足人们在各种高新技术领域和极限工作环境中的使用需求。面对这种情况,人们尝试将金属与耐高温陶瓷复合来满足使用需要。但对于均匀复合材料(如图1.1(a)所示)来说,它的性质均一,具有各向同性,并且各项性能并不突出,无法满足需要。而层状复合材料(如图1.1(b)所示)是由两种或两种以上不同种类的性质均匀原料复合而成,在材料内部层与层之间存在宏观界面,热膨胀系数、热导率等物性参数在界面处不匹配,在使用时容易导致不同材料间发生剥落。为解决上述复合材料存在的问题,仍需开发出一种新型材料。
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