1. Introduction
Machining sheet metal plays a key role in the forming of the thrust chamber of the liquid rocket engine, the product connection, and the manufacturing of the duct. Compared with ordinary sheet metal parts, the sheet metal parts of aerospace products have the characteristics of various types, complex shapes, high finish, and strict tolerance requirements. Before the sheet metal parts are formed, the first thing to be processed is the shape development and processing of the sheet metal parts. The following methods are usually used for the shape development and processing of sheet metal parts: line drawing milling, wire cutting, plasma cutting, oxyacetylene flame cutting, die stamping, high pressure water cutting and CO2 laser cutting. Each cutting method has its advantages and disadvantages. The accuracy, speed, and cost are all different. There is a certain scope of application in industrial consumption. Choosing one of the most convenient and widely adaptable processing methods is currently the task facing the manufacture of sheet metal parts for liquid rocket engines. Compared with all current cutting methods, sheet metal laser cutting has greater advantages for sheet metal parts of aerospace products.
2. Available options for process planning of typical sheet metal parts
(1) Die stamping;
(2) Wire EDM;
(3) High pressure water cutting;
(4) Sheet metal laser cutting.
3. Why choose sheet metal laser cutting
Because sheet metal laser cutting is often electric cutting, there is no human error. Coupled with the guarantee of fine machine tools, the mechanical accuracy of sheet metal laser cutting is theoretically ±0.02mm, but due to environmental reasons, the actual error is about ±0.05mm. And the layout of sheet metal laser cutting can be arranged by software. Discharge as you want, and the material utilization rate is usually ≥80%. Processing accuracy, cutting surface roughness, heat-affected zone range and processing speed can all meet the requirements of sheet metal parts for aviation products.