Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

Abstract

Cutting tool path has significant effects on the performance of micro nozzles manufactured by micro machining. Different tool paths induced different directions of surface roughness. As for it, the manufacturers need to obtain optimal cutting tool path and cutting parameters. In this article, optimum machining parameters for the fabrication of micro Laval nozzle with two different end milling tool paths are presented. First, surface roughness models for different types of cutting tool paths are proposed. A case of machined nozzle surface is then given to verify the applicability of the developed roughness model. Second, theoretical profile geometries for the Laval nozzle to be manufactured are designed. Third, the influences of surface roughness on the nozzle performance parameters including total pressure, average outlet velocity and thrust are investigated through computational fluid dynamic analysis. Simulated performance parameters are contrasted with their theoretical values. It is found that for different tool paths, the nozzle of axial tool path has larger total pressure and average outlet velocity than that of circular tool path. Moreover, with surface roughness increasing, thrust decreases obviously when surface roughness Rz is larger than 4.8 μm. Micro end milling experiments based on axial tool path are then performed, and the optimum cutting parameters are obtained. Finally, a nozzle was manufactured with the axial tool path as well as the optimized cutting parameters.

Assessment of tool path strategies for milling complex surfaces in hardened H13 steel

“…In this context, when finishing complex surfaces, it is very important to choose the machining strategy as a function of the paths covered by the tool. 16 This will affect the tool–part contact regions, influencing the cutting forces, vibrations, tool wear, and surface finishing. 17…”

“…14,15 In this context, when finishing complex surfaces, it is very important to choose the machining strategy as a function of the paths covered by the tool. 16 This will affect the tool-part contact regions, influencing the cutting forces, vibrations, tool wear, and surface finishing. 17 The roughness and form tolerance values obtained by the machining operation depend on dynamic factors inherent to the process, such as vibrations of the tooltool holder system, and deviation of the cutting tool in relation to the machined surface.…”

Mechanism of dual-direction vibration-assisted (DVA) micro-milling in surface formation considering the tool life-lengthening effect on the Co41Cr16Ni15 alloy: design and experiment

“…Micro-machining has an increasingly widespread utilization in micro-scaled components, across aerospace national defense, electronics and biomedical industries. In the micro-machining field, micro-milling is widely used to achieve ultra-precision processing of thin-wall microstructure [1]- [9] as shown in Fig. 1, with the following characteristics: (1) a wide range of materials for the processed parts Fig.…”

“…1, with the following characteristics: (1) a wide range of materials for the processed parts Fig. 1 Some high precision microstructures made by micro milling [1]- [9] be selected [10] ; (2) the sizes and surface shapes of the processed parts can achieve a higher level of accuracy [11] ; (3) the deterministic processing of parts with complex three-dimensional structures can be achieved [12] ; (4) high material removal rate and high processing efficiency [13] ; (5) low cost of manufacturing equipment and high suitability for production requirements in a variety of small batch parts [14] .…”

Geometric deviation reduction method for interpolated toolpath in five-axis flank milling of the S-shaped test piece

“…In these works, different interpolation algorithms for interpolated toolpath were proposed. 7 Zhang et al 8 presented a parametrical cubic spline curve transitional approach for the interpolation of continuous short line segments. The trajectory error of the transitional curve is deduced according to the constraints of control points.…”