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The paper presents the results of an analysis of the effect of brushing on the edge condition of workpieces with complex geometric shapes, formed during milling, on a five-axis DMU 100 monoBLOCK machining center. A set of EN-AW 7075 aluminum alloy specimens with curvilinear edges requiring multi-axis machining was prepared. The change of edge condition after the milling process was realized using Xebec tools with flexible ceramic fibers. The effects of brush fiber type and parameters related to tool design were analyzed. Different brushing strategies were employed on the five-axis machining center. It was shown that, for curvilinear edges, there were different effects for concave and convex edges depending on the employed tool strategy, including the type of tool, its configuration, and its orientation towards the workpiece. For a lead angle of β = 0°, the machined edge was characterized by variable chamfer widths, in spite of maintaining other machining parameters constant. The use of a lead angle β > 0 produced a stable edge with repeatable characteristics. The range of fiber interaction increased with increasing the lead angle and fiber working length. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) of auxetic structure is gaining prominence for various fields ranging from structural material to biomaterials. This work proposes a novel design of the auxetic structure with regular honeycomb, i.e. hybrid auxetic structure. Additionally, a sharp corner of the auxetic structure is replaced with a fillet feature to stiffen the structure by suppressing the hinging mechanism. All models are fabricated in extrusion-based AM technique using Polylactic acid (PLA) material. A comparison study was carried out on 3D printed samples that were subjected to uniaxial tensile load. To understand the effect on functional and mechanical properties, a tool path strategy with single-pass and zigzag tool paths was proposed. Solid material properties were used in finite element analysis (FEA) to compare with experimental results. Experimental results indicate that hybrid structure takes more load than auxetic structure. The ultimate tensile strength (UTS) of the hybrid structure was 32% more than that of the auxetic structure. The finite element results are in good agreement with the experimental results. The observation reported in this article will help frame design rules and selection of AM processes for applications ranging from structural protection sandwich constructions with low-density cores to tissue engineering and regenerative medicine scaffolds. [ABSTRACT FROM AUTHOR]

In this study, the effect of four different machining methods consisting of "Trochoidal," "Follow Part," "Zig," and "Zig-Zag" which are common in CAM package programs and used often in the industry has been investigated. Firstly, the 3D model of samples is produced in the CAD program. Models are machined in CNC milling workbench. In order to examine the effect of tool path strategies on tool life, the amount of wear loss as a criterion and the SEM images of tool wear as a supporting criterion are taken into account. According to the results, the "Zig-Zag" tool path strategy is the tool path that causes the highest weight loss in the cutting tool, while the "Trochoidal" tool path strategy causes in the least weight loss in the cutting tool. In addition, the surface roughness of the samples taken from different regions of the model and the operation time of the different tool paths are determined. In this context, the operation time of the test sample is maximum in "Zig" team path strategy, while it is at least in "Follow part" team path strategy. By examining the surface roughness, the best surface roughness values are obtained with the strategy of "Follow Part" and "Trochoidal" tool path, while the worst values are obtained in the "Zig" tool path strategy. As a result of the examination, the optimum tool path strategy for cutting tool life was found to be "Trochoidal" tool path. This work differs from the counterparts as handling the AISI X210Cr12 steel which make the paper first in determining the effect of tool path strategies on machinability. Lastly, obtained findings are useful for the organization of this type of steel in manufacturing chain of industrial companies. [ABSTRACT FROM AUTHOR]

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Intelligent machining is a current focus in advanced manufacturing technology, and is characterized by high accuracy and efficiency. A central technology of intelligent machining—the cutting process online monitoring and optimization—is urgently needed for mass production. In this research, the cutting process online monitoring and optimization in jet engine impeller machining, cranio-maxillofacial surgery, and hydraulic servo valve deburring are introduced as examples of intelligent machining. Results show that intelligent tool path optimization and cutting process online monitoring are efficient techniques for improving the efficiency, quality, and reliability of machining. [ABSTRACT FROM AUTHOR]

This paper presents the findings of experimental investigations into the effects of tool path strategies on fatigue life of high-speed ball-end-milled AISI H13 steel. Milling operations were conducted under three different tool path strategies with four levels of feed per tooth 0.1-0.4 mm/z. Fatigue life of machined samples was tested by three-point bending fatigue tests. Results show that the fatigue performance is susceptible to tool path strategies. Different tool path strategies bring the difference in microscopic stress concentration induced by the orientational surface topography and the effective residual stress defined as the residual stress component along the applied tensile stress direction. These two aspects can alter the real maximum tensile stress suffered by the milled surface and then influence the fatigue performance. Moreover, optimization methods for the tool path selection are put forward based on the findings that the effective residual stress has more significant influence on fatigue performance than the microscopic stress concentration and the more compressive the residual stress is, the longer the fatigue life will be. This study indicates that the fatigue performance for a ball-end-milled surface can be improved from the tool path control point of view. [ABSTRACT FROM AUTHOR]

Compared to milling on a macro scale, the micromilling process has several cumbersome points that need to be addressed. Rapid tool wear and fracture, severe burr formation, and poor surface quality are the major problems encountered in the micromilling process. This study aimed to reveal the effect of cutting path strategies on the cutting force and surface quality in the micromilling of a pocket. The hatch zigzag tool path strategy and the contour climb tool path strategy under different cooling conditions (e.g., dry, air blow, and flood coolant) at fixed cutting parameters. The micromilling tests revealed that better results were obtained with the use of the contour tool path strategy in terms of cutting forces (by up to ~43% compared to the dry condition) and surface quality (by up to ~44% compared to the air blow condition) when compared to the hatch tool path strategy. In addition, the flood coolant reduces the cutting temperature and eliminates chips to significantly enhance the quality of the micro milled surface. [ABSTRACT FROM AUTHOR]

Compared to milling on a macro scale, the micromilling process has several cumbersome points that need to be addressed. Rapid tool wear and fracture, severe burr formation, and poor surface quality are the major problems encountered in the micromilling process. This study aimed to reveal the effect of cutting path strategies on the cutting force and surface quality in the micromilling of a pocket. The hatch zigzag tool path strategy and the contour climb tool path strategy under different cooling conditions (e.g., dry, air blow, and flood coolant) at fixed cutting parameters. The micromilling tests revealed that better results were obtained with the use of the contour tool path strategy in terms of cutting forces (by up to ~43% compared to the dry condition) and surface quality (by up to ~44% compared to the air blow condition) when compared to the hatch tool path strategy. In addition, the flood coolant reduces the cutting temperature and eliminates chips to significantly enhance the quality of the micro milled surface.

It is hypothesized that the orientation of tool maneuvering in the milling process defines the quality of machining. In that respect, here, the influence of different path strategies of the tool in face milling is investigated, and subsequently, the best strategy is identified following systematic optimization. The surface roughness, material removal rate and cutting time are considered as key responses, whereas the cutting speed, feed rate and depth of cut were considered as inputs (quantitative factors) beside the tool path strategy (qualitative factor) for the material Al 2024 with a torus end mill. The experimental plan, i.e., 27 runs were determined by using the Taguchi design approach. In addition, the analysis of variance is conducted to statistically identify the effects of parameters. The optimal values of process parameters have been evaluated based on Taguchi-grey relational analysis, and the reliability of this analysis has been verified with the confirmation test. It was found that the tool path strategy has a significant influence on the end outcomes of face milling. As such, the surface topography respective to different cutter path strategies and the optimal cutting strategy is discussed in detail. [ABSTRACT FROM AUTHOR]