Point segregation and temper brittle intergranular fracture

准备实验

这项实验是在一个完备的材料实验室进行的，实验室设备包括有活动工作台，电子镜，用于组装薄板及定位装置等。薄板在实验室里购入时是带有加热袋和保护膜的，以防止表面污染和损坏，而且还要检查薄板的尺寸和材料的品质。应该使用玻璃钢定位装置和活动工作台，以确保薄板的水平安装和固定。因为本实验将测试不同的电镀层厚度，所以实验室里有一套能产生可调节的铻涂层的设备是必要的。

实验过程

实验开始前，对钢板进行精确的磨削抛光，以便于铻涂层的形成，并且使得铁板可以容易地被观察。然后，将调整电镀涂层厚度的设备设置在削剔后的钢板表面上，以一定的速度将涂料加以积累，以形成不同厚度的涂层，同时确保涂料的均匀性。紧接着，把熔解定型涂料加热，以使它从粉末变为均匀的液体，并将涂料浸渍到涂层内，以形成有用的涂层组织。

接下来，将涂层浸入一定的温度的回火炉，以实现热处理和成形处理，使涂层金属能够达到所需的性能要求。同时，在低温回火处理过程中，还要测量涂层厚度，以确定处理过程中是否发生变化。最后，将涂层薄板按照纵横断口的方式切割，并将钢板的节点状的偏析和回火脆沿晶断口的形态状进行观察和测量，其结果会用于下一步实验中的分析处理。

数据分析

根据实验得出的结果，可以对涂层的厚度，节点状的偏析和回火脆沿晶断口的形态状等特性进行详细的研究和分析。厚度利用无线电技术（RFT）来测量任何一个尺寸上的金属表面涂层，以得到简单准确的结果。接着，研究人员还要利用电镀涂层和回火处理中的微米尺度的空间组织结构来观察节点状偏析和回火脆沿晶断口的形态，使用电子显微镜来查看和放大节点和断口。最后，结合实验获得的实际数据和图像，利用数据处理软件的功能，对节点状偏析和回火脆沿晶断口的形态状进行数据分析，用于更深入了解涂层的物理和化学性能。

结论

经过上述的实验流程，实验室研究者可以得到电镀涂层的厚度，节点状偏析和回火脆沿晶断口的形态状及其相关性能的准确信息。因此，基于上述实验数据，研究人员可以进一步深入了解电镀涂层的相关性能，为改善电镀工艺及产品质量提供了有效的支撑性信息。

Experiment Preparation

This experiment was conducted in a complete material laboratory, which was equipped with operation tables, electronic microscope, assembling and locating devices for thin plate. When the thin plate is purchased in the laboratory, it is equipped with heating bag and protective film to prevent surface contamination and damage, and it is necessary to check the size and quality of the material. Glass steel locating device and mobile work table should be used to ensure the level installation and fixation of the thin plate.

Tensile fracture is a type of fracture that occurs in materials as a result of tensile stress. It is one of the most common types of failure in materials, such as metals and polymers, and is characterized by a necking process that causes material to fracture in a way that forms a distinct V- or U-shaped cross-section.

Tensile fracture can be further divided into two types according to the shape and width of the crack formed at the point of fracture. In brittle tensile fracture, relatively small cracks form in a V-or U-shape and propagate across the material along the direction of maximum stress. This type of fracture is usually characterized by a fine-grained microstructure. In ductile tensile Fracture, relatively large cracks propagate along the grain boundaries, while a series of smaller intergranular cracks form in between grains. The crack surface is often characterized by fine grain-shaped ridges.

Tensile fracture can also be affected by heat treatment. When a tensile specimen is heated and cooled, the microstructure of the material changes and becomes more homogeneous. This process can lead to an increase in the ductility of the material and reduce the chances of brittle tensile Fracture. In addition, heat treatment can reduce the size of the intergranular cracks and create a more uniform distribution of grain boundaries, which can also help reduce the risk of ductile tensile Fracture.

Overall, tensile fracture is an important mechanism of failure in many materials and can be controlled by both material selection and heat treatment. By understanding the microstructural features of the material, the fracture mechanism can be better controlled to prevent failure.