Among the various methods of joining metal structures, welding occupies an irreplaceable central position. A welded joint is defined as a component or structure formed by heating, applying pressure, or a combination of both, to achieve a permanent bond at the atomic level between two or more separate metal components.

I. Five-axis machine structure features and working principle 1. Definition of five-axis: a machine tool with at least five coordinates, respectively, three linear coordinates and two rotary coordinates, and five axes. 2. Five-axis machining features: 1.