The Effects of Milling Strategies on Forces, Material Removal Rate, Tool Deflection, and Surface Errors for the Rough Machining of Complex Surfaces

Abstract

Sculptured/curved surfaces, today, are widely used in several industries, for instance, automotive, aerospace, bio-medical components, precision machine design and die-mould industries. Recent improvements in CAM software have allowed the manufacturing of complex curved geometries. The ball-end/nose milling is a flexible process that is capable of milling both convex and concave part surfaces with rough, semi-rough and finish processes. The sculptured surface milling is mostly realized by the repeated motion of a rotating cutter along predefined trajectories. Manufacturing engineers can choose the cutter paths generation approach from a set of typical paths (zig, zig-zag, concentric, radial tool paths, etc.) in commercial CAM software. In addition, these strategies cannot be optimized for all complex surfaces to be milled. A substantial number of studies have examined this subject, and many path-generation approaches have been developed, as shown in Fig. 1 [1] and [2].The strategies can be sorted into three basic categories: offset, single direction, and raster. In offset milling, the cutter starts at the periphery of the face and then proceeds spirally inwards. In a raster milling strategy (zig, zig-zag, or sweep) the cutting tool moves back and forth across the milled workpiece [3]. In spiral milling, the cutter returns to the start-point of each cycle and then cuts outwards to the next outer cycle. When using a spiral strategy, the cutting time is hugely decreased. The selection of the proper milling strategy in the process of milling will decrease cutting time, improve the surface quality of the finished part and tool life and reduce machining costs and cutting forces. Kurt

An Analysis of the Surface Geometric Structure and Geometric Accuracy of Cylindrical Gear Teeth Manufactured with the Direct Metal Laser Sintering (DMLS) Method

“…Parts made of GP1 stainless steel can be machined, welded, beadblasted (sand-blasted), and polished; spark erosion and coating may also be applied [16]. Regarding the gear wheels, the material GP1 is used mainly in the chemical industry due to its anti-corrosive and selflubricating properties, e.g., in gear pumps [19] and in drive systems of radial flow sedimentation tanks [20]. In this study, the smallest possible layer thickness in the processing of GP1 was 0.02 mm.…”

Increasing the Accuracy of Free-Form Surface Multiaxis Milling

“…The tool axis inclination against a workpiece has a significant influence on the size and direction of the cutting forces [1,2] (it means the individual cutting force components). The radial, axial, and tangential cutting forces tend to push the tool apart.…”

“…Studies on the contact of the tool with the workpiece are described in [3,7,13]. The deformation deflection of the cutting tools or the deformation of the machined parts are mentioned in [1,8,14,15]. The problem of the durability of the cutting tool is described in the literature [16][17][18].…”

Optimization Parameters of Milling Process of Mould Material for Decreasing Machining Power and Surface Roughness Criteria

“…Recently, investigators solved the trade-off among multiresponses regarding surface quality, energy consumed, and processing efficiency. The technological responses included are cutting energy [11], tool wear [12], cutting force [13][14][15][16], residual stress [17], material removal rate [18], and machining time [19]. Additionally, the surface geometry [20], chip formation [21,22], micro-hardness, and microstructure [23] were considered as important technical outputs.…”