Hot Extrusion Dies

High pressures, elevated temperatures, complex and intricate section geometries lead to repeated mechanical and thermal stresses in the extrusion die and affiliated tooling. The focus of this monograph is on the following three distinct yet inter-related studies pertaining to the improvement of aluminum extrusion die: failure analysis, surface treatment, and effect of billet quality. The following topics are discussed in detail: investigation of various modes and critical failure types based on industrial data; FE simulation for identification of critical process parameters & design features in die fatigue-life; analysis of gas nitriding process for H13 steel and investigation of various effects including repeated nitriding, pre-nitriding surface preparation and die profile geometry on the nitriding performance; investigation of the effect of billet quality and related influencing extrusion parameters on the die service life; regression-based die life models; microstructural investigation of different billet samples and FE analysis of extrusion process to observe the influence of smelter (primary) and recycled (secondary) billets on the useful life of extrusion die.