Failure modes of bucket teeth in excavator casting

The bucket teeth need to bear the impact and bending moment from the material when contacting the material. During the working process, the surface of the bucket tooth tip often appears various furrows, spalling and deformation after the big impact on the bucket tooth tip, resulting in surface wear or falling off. Therefore, to improve the hardness and wear resistance of bucket teeth is the main solution. At the same time, it also needs to solve the problem of strength and toughness without bending and breaking under the impact and cantilever force.

The main failure mode of bucket teeth is abrasive wear failure, but the wear degree of bucket teeth under different working conditions is also quite different, mainly including low impact abrasive wear and high impact abrasive wear. When the bucket teeth are subjected to high impact, such as digging some materials with high hardness, there are two kinds of wear. The first is that the wear type of bucket teeth is chiseling abrasive wear when meeting sharp objects; the second is that when a blunt object is encountered, a furrow will appear after the object slides over the surface of the bucket tooth, and the object will squeeze the metal in the groove to both sides without cutting. Under the repeated action of the object, the metal on both sides of the furrow will be flattened or new furrows and changes will appear In this way, the surface of the bucket tooth will be hardened by repeated plastic deformation, and the stress concentration appears on the surface of the bucket tooth. This kind of wear is called the fracture wear mechanism caused by repeated plastic deformation. Under the action of low impact, when the bucket teeth excavate the hard objects, the final damage to the bucket teeth is called low cycle strain fatigue wear.

The above wear is the main wear mode of bucket teeth failure, and the actual wear process is the result of the joint action of several kinds of wear.