摘 要

在颗粒几何特性与表征中，颗粒尺寸的测量十分重要，且随着技术的发展，对粒度测量的要求越来越高。在各种粒度测量方法中，因原理不同，适用的条件不同，测试性能也不尽相同。如其中的沉降法，适用浓度较高，可靠性较好，但测试耗时较长。而激光法测试便捷速度快，测试范围广，但适用浓度低。

课题组研制了一种新型颗粒共沉降装置，利用颗粒粒度和密度的差异在液体中连续沉降堆积，可以有效形成组分和结构连续变化的梯度材料。其中形成梯度材料的颗粒尺寸对材料的性能及用途影响显著，因此需要对新型装置的沉降粒度表征性能进行分析，并探讨因素影响的变化规律。

本研究以该新型颗粒共沉降装置为基础，利用沉降液中，颗粒的激光散射像点在铅锤方向上的运动距离变化，通过影像实时图像分析，获取各颗粒的沉降速度，进而通过Stokes公式获得对应颗粒的Stokes粒径，并通过不同沉降速度范围的颗粒比率，获得粒度分布统计信息，据此计算出各种颗粒的平均粒径。最后基于常用的激光粒度测量结果与该沉降粒度相比较，对颗粒尺寸进行修正。

在测量颗粒粒度的同时，本研究还以沉降浓度为变量，研究其变化对粒径测量的影响。通过初测选取合适的浓度，然后设置浓度梯度，控制变量分组进行测量，将所得到的各组粒度分布与粒径进行对比分析。该新型颗粒共沉降装置不仅能测试粉体粒度分布，而且实现了对共沉降形成组分和结构连续变化梯度材料的在线检测和控制。

关键词：梯度材料，粒度测试，共沉降，沉降浓度，粒径分布

Abstract

Particle size measurement is very important in the geometrical properties and characterization of particles, and with the development of technology, the requirement of particle size measurement is getting higher and higher. In a variety of particle size measurement methods, due to different principles, the applicable conditions are different, test performance is not the same. Such as the settlement method, for a higher concentration, reliability is better, but the test takes longer. The laser method is easy to test fast, wide range of tests, but the application of low concentration.

The research group developed a new type of particle co-sedimentation device, the use of particle size and density differences in the liquid continuous settlement and accumulation, can effectively form a continuous change in composition and structure of the gradient material. The particle size of the material forming the gradient material has a significant effect on the performance and application of the material. Therefore, it is necessary to analyze the performance of the sedimentation grain size of the new device and to explore the variation of the influence of the factor.

Based on the new particle co-settling device, the moving distance of the laser scattering image of the particles in the direction of the hammer is changed by the real-time image analysis, and the sedimentation velocity of each particle is obtained by the Stokes formula The Stokes particle size of the corresponding particles was obtained, and the particle size distribution statistics were obtained by the particle ratios of different settling velocity ranges, and the average particle size of the various particles was calculated. Finally, the particle size is corrected based on the results of the commonly used laser particle size measurements compared to the sedimentation size.

In this paper, the effect of the change on the particle size measurement was studied by measuring the particle size. The appropriate concentration was selected by the initial measurement, then the concentration gradient was set and the control variables were grouped for measurement. The resulting particle size distribution and particle size were compared and analyzed. The new particle co-settling device not only can test the particle size distribution of the powder, but also realize the on-line detection and control of the coprocessing component and the continuous gradient of the structure.

Keywords: Gradient material, particle size test, co - sedimentation, sedimentation concentration, particle size distribution

目录

摘 要 III

Abstract IV

第1章 绪 论 1

1.1 梯度材料的制备方法及研究背景 1

1.2 粒度测试技术的发展 2

1.2.1粒度测试技术背景 2

1.2.2常见的粒度测试技术 2

1.2.3现存较突出的问题 3

1.3 本研究的内容及意义 4

1.3.1课题目标 4

1.3.2课题内容 4

1.3.3课题意义 4

第2章 实验探索 5

2.1实验仪器 5

2.1.1、仪器概况 5

2.2.2、共沉降仪组成 5

2.2实验原理 8

2.3实验过程 9

2.3.1实验设计 9

2.3.2实验步骤 9

2.3.3实验现象 10

第3章 沉降粒度性能研究 11

3.1数据分析 11

3.1.1 悬浮液浓度对平均粒径的影响 11

3.1.2 颗粒密度对平均粒径的影响 12

3.1.3 对其他粒径的影响 12

3.1.4激光粒度仪测试结果的修正 14

3.2拓展探讨 14

3.3误差分析 15

3.3.1操作误差 15

3.3.2仪器误差 15

3.3.3客观误差 16

3.4结论总结 16

3.4.1沉降规律 16

3.4.2仪器修正 16

参考文献 17

致 谢 18