Some zero-moving parts of the machine tool, such as slides and guide rails, shafts and sliding bearings, worms and worm gears, often have scratches or grooves on the surface after running for a period of time. We call this phenomenon a wound. . The grinding damage destroys the precision of the machine tool and affects the service life of the machine tool. If the repair is not timely, the particles generated by the grinding will also intensify the grinding injury, and the groove generated by the grinding will easily hide the dirt and will also intensify the wounding. In severe cases, the sliding members of each other can stop sliding and cause seizure. The wounding is essentially the wear under abnormal conditions. The common wounds on the machine tool can be divided into two types according to the cause: one is the adhesive wear type and the other is the abrasive wear type. . I will give a brief introduction to the causes, preventive measures and repair methods of these two types of wounds. Next page
First, the adhesive wear of this type <br> <br> RESEARCH REVIEW injury injury refers to a material during relative movement of the friction pair, due to friction with each other, the contact surface from one surface to the other, so that the surface friction produced scratches With grooves.
1. Research on the mechanism of the wear-and-wear type of wounds shows that the surface condition of the solid surface has defects of unevenness from the microscopic point of view. Even after polishing, the peaks and valleys cannot be completely eliminated. When the two friction surfaces are in contact, the peaks of the two friction surfaces are actually in contact with each other. Since the contact stress is so large that elastic and plastic deformation occurs, the contact area is increased until it can withstand the full load. In this case, a firm sticking point will appear on the metal contact surface, which is commonly referred to as cold solder adhesion. These sticking points are produced without a surface film. When there is a surface film on the rubbing sub-surface, it is only subjected to the normal force, and the cold soldering adhesion is not generated. If there is a tangential force at the same time, and the normal force and the tangential force are both large, and the relative sliding, the temperature of the friction surface will increase, and under high temperature and high pressure, the oil film will be destroyed, and the contacted metal surface It softens or melts, and the point of contact creates a process of adhesion-avoiding-adhesive-avoiding, which causes the material of the contact surface to transfer from one surface to the other, thereby making one surface (or both surfaces) Scratches and grooves are formed, that is, a wear-resistant type of wound is formed.
2. Classification of Adhesive Wear Types According to the degree of damage of the friction surface, we can classify the common wear-type wounds on the machine into four categories: