一、前言 在航空零件上,孔的内表面加工质量好坏对零件的使用性能影响很大,尤其对零件的疲劳性能影响更大。飞机和发动机的带孔零件,在使用中大多数是在孔的内表面上或在孔的两端尖角部位产生疲劳源。在交变载荷的作用下,疲劳源进而发展成疲劳裂纹,最后导致灾难性的疲劳破坏。因此,提高孔内壁的疲劳强度是航空制造者的重要任务之一。 孔内壁挤压强化是提高疲劳强度行之有效的好方法。内孔挤压强化是用与孔的形状相同的挤压棒,推过或拉过孔,使之达到一定的尺寸精度、表面光洁度和在内表面产生强烈的塑性变形层,此变形层叫做冷作硬化层或挤压强化层。在强化层内产生与基体有区别的组织结构和应力状态,从而提高孔内壁的疲劳强度。本 First, the preface In the aviation parts, the inner surface of the hole processing quality is good or bad on the part of the performance of a great impact, in particular, the greater part of the fatigue performance. The hole parts of aircraft and engines, most of which are fatigue sources on the inner surface of the hole or at sharp corners at both ends of the hole during use. Under alternating loads, the fatigue source develops into a fatigue crack that eventually leads to catastrophic fatigue failure. Therefore, improving the fatigue strength of the inner wall of the hole is one of the important tasks of the aviation manufacturer. Hole wall extrusion is to enhance the fatigue strength of a good method. The inner hole extrusion is enhanced with the same shape with the hole extrusion rod, pushed or pulled through the hole, so as to achieve a certain degree of dimensional accuracy, surface finish and the inner surface of the strong plastic deformation layer, the deformation layer is called cold For the hardened layer or extruded layer. In the reinforced layer with the matrix structure and stress are different from the state, thereby increasing the fatigue strength of the inner wall of the hole. this