Fracture and wear in shredder hammer tungsten carbide tips in the sugar cane shredding process

Abstract

This paper reports on facture and wear of damaged shredder hammer tips manufactured from cemented tungsten carbide with an ultrafine grain structure and Ni-Ti-Cr as a binder instead of Co, for sugar cane shredding. Optical imaging and scanning electron microscopy were applied for measurement of fracture and wear regions of damaged shredder hammer tips at macro and microstructural scales. Our results reveal that edge and large scale fractures in the form of conchoidal fracture were caused by impacts from hard objects such as rocks or tramp metal materials in the shredding process. Minor wear occurred due to abrasive wear of tungsten carbide grains and fatigue-induced cracks in the metal binders. This study shows that fracture was the main failure mode of the trial cemented tungsten carbide used that caused the instant failure of the shredder hammer tips, while minor wear also occurred.