Failure analysis of shot–sleeves used in brass high pressure die–casting process

Abstract

A failure investigation has been conducted on a two cases of shot-sleeve used in brass–die casting and made up of AISI H10 tool steels to study their failure mechanisms. The chemical composition of the shot–sleeves material and the hardness profiles were evaluated. A preliminary examination of shot–sleeves reveal the presence of cracks network on their inner surfaces which proves that thermal fatigue was probably the main cause of their failure. A Meticulous investigation of these damaged surfaces reveal the presence of an additional small zone cited in the vicinity of the plunger entry side. This zone presents several scratches sign of abrasive wear. Then, the measurement of the cracks length and their linear density along longitudinal and transversal cuts of the damaged shot–sleeve sample are carried out. Results show that the observed cracks network can be divided into two zones. The first one was the most damaged in terms of cracks density and length given that it is the first zone which enter in contact with the molten metal. However, the cracks network examined in the second zone appears to be superficial.