Polishing of metallographic specimens

Polishing of Gold Alloy Samples

Gold alloys consist of two or more elements, primarily gold and one or more other elements. Gold alloys are used in everything from jewelry to electronics, and as such, they must be polished to perfection in order to meet the high standards of these products. In order to properly polish gold alloy samples, there are several steps to follow.

First, the sample should be placed in a small container that can hold the sample but has enough room for polishing. Next, a thin coat of abrasive or polish should be applied to the sample using either a brush or a polishing cloth. This will help to remove small scratches and imperfections and prepare the sample for further polishing.

Next, a buffing wheel should be used to evenly spread the abrasive or polish. This should be done slowly and with light pressure; too much pressure can damage the sample. The buffing wheel should continue to be moved in small circles in order to reach all areas of the sample.

Once the sample has been polished, it should be rinsed with warm, soapy water. This will help remove any residual abrasive or polish and keep the sample clean. Next, a finishing polish should be applied in order to bring out the luster and shine of the sample. A soft cloth should be used to rub the polish in a circular motion until desired results are achieved.

Finally, the sample should be wiped off with a clean cloth in order to preserve its newly polished shine. Any excess polish should be removed. Once done, the sample will be ready for use.

Polishing gold alloy samples requires patience and attention to detail in order to get the best possible results. By following the steps outlined here, it is possible to achieve a stunningly polished gold alloy sample that is sure to shine for years to come.

Gold etching test is a kind of metallographic examination method that is used to determine the accuracy and surface condition of machine parts or components. It is mainly used to evaluate the surface texture or surface condition of products, to identify surface defects such as wear and tear and pitting, and to monitor the consistency of roughness and/or smoothness.

The gold etching test method is based on the differences in chemical and mechanical characteristics of various surface materials. The solution used in gold etching test method is usually composed of nitric acid and hydrofluoric acid, which is heated and agitated to achieve the required etching conditions. In this process, the surface of the sample part is immersed in the solution, and an etching reaction occurs, producing complex microscopic images on the surface of the sample that are used to analyze the characteristics of the surface.

Gold etching test is widely used in mechanical industry, such as automobile, aerospace and shipbuilding. In mechanical industry, gold etching test is commonly used to inspect the surface of mechanical parts and components, such as valve body, piston and cylinder head of engines, gear, gear shaft and transmission gear of gearbox, and bearing, spline and shaft of power transmission system. It is also used to measure the surface roughness of machined components and the tolerance of sheet metals.

In conclusion, the gold etching test is a valuable method for inspecting the surface condition of mechanical components by visualizing the microscopic features on their surfaces. It can be used to monitor the quality and consistency of surface textures and identify surface defects.