在金属结构的连接方式中，焊接占据着无可替代的核心地位。所谓焊接件，是指通过加热、加压或两者并用，使两个或以上分离的金属构件在原子尺度上实现永久结合而形成的组件或结构。

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.