Static and fatigue behavior of hydraulic components produced by different additive manufacturing processes

Abstract

This study focuses on hydraulic components’ behavior to significant pressure loads both in static and fatigue conditions. This hydraulic block commonly used on large machines (earthmoving, mining, agriculture…) was initially designed to be machined but has been topologically optimized for additive manufacturing methods: laser powder bed fusion (L-PBF), metal binder jetting (MBJ) and lost-wax casting. The material chosen was a martensitic precipitation-hardening stainless steel that provides good corrosion resistance and high mechanical properties. Most of the samples were obtained with laser powder bed fusion and underwent static and fatigue pressure tests, exceeding the technical specifications of the end user. The tested samples have then been screened and went through various fatigue finite element analyses. This approach demonstrated that all the critical fatigue failure locations obtained experimentally were predictable through software simulation, local non uniform roughness and residual stress in failure areas being key factors for good correlation.