Evaluation of tool performance and wear through vibration signature analysis in drilling of IS3048 steel

In this paper, a connection between vibration amplitude and tool wear when drilling of IS3048 steel utilizing different dimensioned tools is dissected through tests. Discriminant features, which are sensitive to drill wear and breakage, were developed. These were discovered to be somewhat impervious toward sensor location and cutting conditions. In the process, the vibration amplitude features a checking highlight dependent on ascertaining both the tools and their performance over vibrations, which was discovered to be somewhat powerful for on-line identification of drill tool breakage in both frequency and time domains. These vibrational amplitude signal features are directly affected, related to the tool geometry, which give higher chances of tool selection criteria during the drilling process. The experiments were carried out using solid carbide tool with change in tool geometry under dry conditions where the vibration amplitude for both is evaluated. The results revealed that cutting tool vibrational amplitude and tool wear were relatively dependent showing the tool selection of suitable tool geometry.

Investigating the impact of chucks on the stability of a milling process

The impact of a tool chuck on the dynamic stability of a milling process with an end mill was investigated using a workpiece made of aluminium wrought alloy V95pchT2. To assess the dynamic stability, we analysed a Fourier transformed signal recorded during milling using a Shure PGA81 -XLR tool directional microphone. The milling was performed on an HSC75 linear high-production machining centre with an H10F solid carbide end mill. Cutting conditions were calculated based on a stability diagram derived from an operational modal analysis of a manufacturing system. The surface roughness was measured with a Taylor Hobson Form Talysurf i200 contact profilometer. Performance defined by the rate of material removal and the roughness of a treated surface was used to evaluate the cutting process. A correlation was found between the type of tool chuck fixating the end mill, the rate of material removal and the roughness of the machined surface. It was found that, for milling using a power chuck, the areas of stable cutting correspond to the max imum cutting depth equal to 5.6 mm at a cutting width of 16 mm and a cutting feed of 0.1 mm/rev. However, for the other studied chucks, this indicator was 20 to 30% lower. End milling conducted using a power chuck with a solid carbide cutter with a diameter of 16 mm and three cutting teeth resulted in dynamically stable cutting with the highest material removal rate (575.6 cm3/min) and minimum surface roughnes s (0.56 μm). Based on the conducted analysis, for the operation of end milling on a machine with computerised numerical control (CNC), a power tool chuck is recommended that improves milling performance by over 25% relative to the considered tool setups. Furthermore, this preserves the quality of a treated surface and increases the tool cutting life owing to dynamically stable cutting.

Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy

Copper-Beryllium alloys have excellent wear resistance and high mechanical properties, they also possess good electrical and thermal conductivity, making these alloys very popular in a wide variety of industries, such as aerospace, in the fabrication of tools for hazardous environments and to produce injection molds and mold inserts. However, there are some problems in the processing of these alloys, particularly when these are subject to machining processes, causing tools to deteriorate quite rapidly, due to material adhesion to the tool’s surface, caused by the material’s ductile nature. An assessment of tool-wear after machining Cu-Be alloy AMPCOLOY 83 using coated and uncoated tools was performed, offering a comparison of the machining performance and wear behavior of solid-carbide uncoated and DLC/CrN multilayered coated end-mills with the same geometry. Multiple machining tests were conducted, varying the values for feed and cutting length. In the initial tests, cutting force values were registered. The material’s surface roughness was also evaluated and the cutting tools’ edges were subsequently analyzed, identifying the main wear mechanisms and how these developed during machining. The coated tools exhibited a better performance for shorter cutting lengths, producing a lower degree of roughness on the surface on the machined material. The wear registered for these tools was less intense than that of uncoated tools, which suffered more adhesive and abrasive damage. However, it was observed that, for greater cutting lengths, the uncoated tool performed better in terms of surface roughness and sustained wear.

Analysis of Abrasives On Cutting Edge Preparation By Drag Finishing

Cutting edge preparation has become more important for tool performance. The micro-shape, radius and surface topography of the cutting edge plays a significant role in the machining process. The cutting edge of solid carbide end mills have some micro-defects after grinding. For eliminating aforementioned problem, this study investigates drag finishing (DF) preparation for solid carbide end mills reconstruct cutting edge micro-geometry. This paper is to present the design of DF experimental set-up and analysis the characterization of various abrasive media (K3/600, K3/400, HSC 1/300 and HSO 1/100) on the evolution of the surface /roughness along the cutting edge. In parallel, the mechanism of material removal and the kinematics trajectory of the drag finishing are presented. In fact, the form factor (also called as “K-factor”) of the cutting edge micro-geometry is quantified. Comparing with four lapping media, the higher material removal rate (MRR) and the lower surface roughness are obtained by HSO 1/100 abrasive process. The results show that the cutting edge K-factor, MRR and surface topography are influenced by the abrasive particles size, composition and process time. The cutting edge micro-geometry is measured through Scanning Electron Microscopy (SEM) and 3D Optical measuring instrument.

Influence of the Tool Wear on the Quality and Service Life of Gears for the Geared Turbofan Technology Machined by Five-Axis Milling

The geared turbofan technology is one essential way to reduce the fuel consumption, the environmental footprint and the noise pollution of civil aircrafts. An added gearbox between the fan and the low-pressure compressor that reduces the fan speed, which allows higher bypass ratios, achieves the mentioned benefits of geared turbofans. To withstand the high mechanical loads, large double helical gears are used. Gear hobbing and gear grinding require large tool maneuvering spaces. This leads to a larger required space between the single gears of the double helical gear. As a result, the gears are larger and heavier, which leads to a reduced economy of the aircraft. The tool maneuvering space of five-axis milling with solid carbide end mills is much smaller. This enables the design of smaller, lighter and more efficient aircraft engines. However, manufacturing these gears in tolerances better than IT5 is very challenging on five-axis milling machine tools. This paper presents investigations about finish machining of hardened gears on five-axis machine tools. In the investigations performed, varying tool substrates and tool coatings have been investigated together with tool travel paths in order to reduce the tool wear, which is key to achieve the demanded tolerances. Finally, the five-axis milled gears were compared to conventionally manufactured gears on test benches to enable statements regarding the expectable service lives of the manufactured gears.

ANALYZING THE PERFORMANCE OF CIRCLE SEGMENT END MILL WITH PCD INSERTS WITH LASER-MACHINED INTEGRAL CHIPBREAKER WHEN DRY MILLING OF ADDITIVE MANUFACTURED TI-6AL-4V TITANIUM ALLOY

Components with generally shaped surfaces requiring higher surface quality and dimensional accuracy are, in most cases, machined. Specifically, milling technology is involved very often, which can be supplemented by finishing operations. Besides standard ball-nose end mills, circle segment end mills are modern type of cutter that has begun to be used with the development of advanced computer aided machining software, that allows to work with these shaped tools. In this research, comparing the performance of these two modern shaped end mills was investigated. One tool was a commercially available coated solid carbide circle segment end mill. A second prototype end mill with the same profile but different geometry was made with a PCD insert, that additionally had a chipbreaker produced by laser technology. Machining was carried out on the workpiece material the Ti-6Al-4V that was manufactured by additive manufacturing (AM) technology – selective laser melting (SLM). The titanium complex parts are generally used in the transport industries and medicine. Milling tests were performed under dry cutting conditions. The evaluation was based on the force load, the roughness of the machined surface and tool wear. The higher total forces were measured by the tool with a PCD insert, because a different tool geometry was used, despite the use of integral chipbreaker, which allows a partial change of the cutting geometry of the insert. The geometry of end mills with brazed insert is limited by the production process.

Simulation-Based and Experimental Investigation of Micro End Mills with Wiper Geometry

One of the major advantages of micromachining is the high achievable surface quality at highly flexible capabilities in terms of the machining of workpieces with complex geometric properties. Unfortunately, finishing operations often result in extensive process times due to the dependency of the resulting surface topography on the cutting parameter, e.g., the feed per tooth, fz. To overcome this dependency, special tool shapes, called wipers, have proven themselves in the field of turning. This paper presents the transfer of such tool shapes to solid carbide milling tools for micromachining. In this context, a material removal simulation (MRS) was used to investigate promising wiper geometries for micro end mills (d = 1 mm). Through experimental validation of the results, the surface topography, the resulting process forces, and tendencies in the residual stress state were investigated, machining the hot work tool steel (AISI H11). The surface-related results show a high agreement and thus the potential of MRS for tool development. Deviations from the experimental data for large wipers could be attributed to the non-modeled tool deflections, friction, and plastic deformations. Furthermore, a slight geometry-dependent increase in cutting forces and compressive stresses were observed, while a significant reduction in roughness up to 84% and favorable topography conditions were achieved by adjusting wipers and cutting parameters.