试剂检测时，镀层的孔隙率为零，这可能要归功于两个原因。

（1）锌粉颗粒的变形导致间隙体积减小从而阻止了通孔的形成。钢球堆垛模型显示，球体之间存在间隙位置，例如每三个球体之间就有一个三角形凹坑。在等尺寸球体(半径为R)堆垛时，因堆垛方式不同间隙位置则有扁八面体、四面体、八面体三种间隙，可能嵌人间院的最大球体半径r称为间隙半径，分别为: 0. 154R、O. 252、0. 41。由此可以看出，等径大球组成密集排列时，它们的间隙中可容纳的小球半径(相当于间隙半径)为大球半径的0. 154~0.41之间，平均为0. 2823R。不同半径球体间的间隙位置和尺寸会发生变化，但规律是存在的。大小球体混乱堆垛时，小球填充大球的间隙位置可以使体系的能量降低。机械镀锌工艺所采用的锌粉中大部分锌粉颗粒的粒径范围为2 ~ 4μm。假设在镀层中大锌粉颗粒和偏大锌粉颗粒形成镀层的构架，小尺寸锌粉颗粒填充间隙，从系统能力降低和排列的难易程度分析，这种假设是合理的。镀层的结构分析也证实了这种假设的合理性，正如间隙位置在理想晶体中是存在的，由锌粉颗粒构成的间隙也存在于镀层中，这些间隙位置部分被更小的锌粉颗粒填充，部分存留下来。

（2）在冲击力作用下,锌粉颗粒或许发生变形，变形可以发生在锌粉沉积成层之前或之后。从尺寸上分析，锌粉颗粒属于微米级，冲击介质(玻璃丸)属于毫米级。当锌粉夹在冲击介质和工件之间时，相当于被挤压于两个大平面之间，优先受力的是大尺寸锌粉颗粒，发生变形亦如此，且称之为机械镀锌过程的择优变形性。在锌粉沉积成层之前的变形使部分锌粉扁化，在沉积后的变形除使锌粉扁化外，还导致间院同时受静水压力和切应力，最终致使间院变形。因此，锌粉沉积之前或之后的变形，都会缩小同家的体积，并且锌粉沉积之后的变形还会造成间家的移动;再加上其他夹杂物(如先导金属等)在中间的填充，使得间家被锌粉和夹杂物隔绝，不会与临近的间家连通。可以认为:在镀层的垂直方向短程范围内间歌存在，长程范围内间家是孤立的，不会相互连接形成通孔。

(1) Deformation of zinc powder particles results in the reduction of gap volume, which prevents the formation of through holes. The steel ball stacking model shows that there are clearance positions between spheres, such as a triangular pit between three spheres. When a sphere of equal size (radius R) is stacked, there are three kinds of clearances: flat octahedron, tetrahedron and octahedron because of different clearance positions. The maximum sphere radius r which may be embedded in the courtyard is called clearance radius, which is 0.154R, O.252 and 0.41, respectively. It can be seen from this that when large spheres of equal diameter are arranged densely, the radius of small spheres (equivalent to the radius of clearance) that can be accommodated in their clearance is between 0.154 and 0.41 of the radius of large spheres, with an average of 0.2823R. The position and size of clearance between spheres with different radius will change, but the law exists. When large and small spheres are stacked in disorder, the clearance position of filling large spheres with small spheres can reduce the energy of the system. The particle size of most zinc powders used in mechanical galvanizing process ranges from 2 to 4 microns. It is reasonable to assume that large zinc powder particles and larger zinc powder particles form the framework of the coating, and small zinc powder particles fill the gap. This assumption is analyzed from the degree of difficulty of system capacity reduction and arrangement. The structure analysis of the coating also confirms the rationality of this hypothesis. Just as the gap position exists in the ideal crystal, the gap composed of zinc powder particles also exists in the coating. Some of these gap positions are filled by smaller zinc powder particles and some remain.
(2) Under the impact force, the grain of zinc powder may be deformed, which may occur before or after the deposition of zinc powder. From the size analysis, zinc powder particles belong to the micron level, impact medium (glass pellet) belongs to the millimeter level. When the zinc powder is clamped between the impact medium and the workpiece, it is equivalent to being squeezed between two large planes. The preferential force is the large size zinc powder particles, so is the deformation, which is called the preferred deformation of mechanical galvanizing process. Deformation before zinc powder deposition makes part of zinc powder flattened. Deformation after deposition not only flattens zinc powder, but also causes the courtyard to be subjected to hydrostatic pressure and shear stress at the same time, which ultimately leads to the courtyard deformation. Therefore, the deformation before or after the deposition of zinc powder will reduce the size of the same home, and the deformation after the deposition of zinc powder will also cause the movement of the home; together with other inclusions (such as lead metals) in the middle of the filling, so that the home is separated by zinc powder and inclusions, will not be connected with the neighboring home. It can be concluded that in the vertical direction of the coating, there exists a song in the short range, while in the long range, the home is isolated and will not connect with each other to form a through hole.

钢准金属 & 钢铁3Q服务

钢准金属专注镀锌板加工配送，6年行业经验，只为提供高品质钢板加工配送服务

更多服务细节，欢迎您来咨询，13380228696（微信同号）

钢准金属官网 www.gzhmetal.com

钢准阿里巴巴旺铺 gzhmetal.1688.com

阿里巴巴企业官网 www.gzhmetal.cn