Process Parameters Optimization of Thin-Wall Machining for Wire Arc Additive Manufactured Parts

Abstract

Additive manufacturing (AM) is an arising production process due to the possibility to produce monolithic components with complex shapes with one single process and without the need for special tooling. AM-produced parts still often require a machining phase, since their surface finish is not compliant with the strict requirements of the most advanced markets, such as aerospace, energy, and defense. Since reduced weight is a key requirement for these parts, they feature thin walls and webs, usually characterized by low stiffness, requiring the usage of low productivity machining parameters. The idea of this paper is to set up an approach which is able to predict the dynamics of a thin-walled part produced using AM. The knowledge of the workpiece dynamics evolution throughout the machining process can be used to carry out cutting parameter optimization with different objectives (e.g., chatter avoidance, force vibrations reduction). The developed approach exploits finite element (FE) analysis to predict the workpiece dynamics during the machining process, updating its changing geometry. The developed solution can automatically optimize the toolpath for the machining operation, generated by any Computer Aided Manufacturing (CAM) software updating spindle speed in accordance with the selected optimization strategies. The developed approach was tested using as a test case an airfoil.

Estimation and Improvement of the Achievable Tolerance Interval in Material Extrusion Additive Manufacturing through a Multi-State Machine Performance Perspective

“…being C a sensibility coefficient included to model possible non-proportionalities between the changes introduced in the design file and the changes in the results. Similarly, when the process is multi-modal but the differences of locations between the intrinsic dispersions is zero, then the deviation between and T shall be used to calculate an optimized design size (XD1) according to Equation (6).…”

“…Tolerance intervals (TI) are expected to be larger in AM than in traditional manufacturing processes [5], and this lack of quality has been usually addressed by adding post-processing steps [6]. Production planning in AM will require trustable information about the expected TI and the fulfillment of tolerance specifications to decide which machine or technology will be used beforehand [7].…”

Special Issue on “Machining Dynamics and Parameters Process Optimization”

“…However, most of these parts still require a machining stage to achieve the required dimensions and surface roughness. Accordingly, Grossi et al [8], presented an approach to predict the dynamics of a thin-walled component produced using wire-arc-additive manufacturing. The knowledge of the workpiece dynamics evolution throughout the machining process is necessary for cutting parameter optimization.…”

A state-of-art review on chatter and geometric errors in thin-wall machining processes

“…1(a). This kind of parts is mainly manufactured by removing a large proportion of material from their initial monolithic blocks to meet the requirements of lightweight design and eco-efficiency [19]. In most studies, these complex components are simplified to a cantilever plate to reduce the difficulties in modelling and analysing the thin-wall machining process, as shown in Fig.…”