Effect of tool geometry and material flow on fsw tool wear: insights into wear processes

Effect of Process Parameters and Tool Geometry on Fabrication of Ni Particles Reinforced 5083 Al Composite by Friction Stir Processing

The Friction Stir Welding (FSW) process has a large industrial potential in the field of joining lightweight alloys. Due to the increasing industrial use of aluminium alloys the benefits provided by this technology are very appealing. However, this potential has not, until this time, become a reality due to the lack of relevant available information concerning the process. The lack of information is especially serious in regards to the welding tools. This component, whose importance in the FSW process cannot be overstated, has not been the subject of extensive published research due mainly to the difficulties related to the modelling of the FSW process, which means that all of the development in this field has to be conducted through a trial and error approach. This approach entails significant costs and success risks, thus reducing the capability of R&D institutions to carry out extensive research. The objective behind the work detailed in this paper is the assessment of the effects of the welding tool geometry and features in the weld quality and process productivity. The work was carried out via an experimental procedure, which consisted of carrying out several welds using different pin lengths, pin diameter, pin geometry and shoulder diameter. The geometries that were used are based on known geometries from literature and new concepts. Due to practical limitations the study was conducted using a 3mm thick AA 6082-T6 butt joint configuration. The quality of the welds was assessed through destructive and non destructive testing, namely a visual inspection, an x-ray and a macrographic examination. These results can then be used to correlate the effects of the different tool geometries with the weld quality and productivity. The process productivity can be, according to [1], directly related to the welding speed, this is due to the near absence of welding consumables in the FSW process, leading to the predominance of fixed costs. The results pertaining to this work enable a better comprehension of the manner by which the tool geometry influences the weld quality and the process productivity, thus providing a stepping stone in the ongoing task of optimizing and modelling of the FSW process. The results presented in this paper may also be useful when extrapolated to other materials and thicknesses.

Chapter 5 - Effects of tool geometry

Review on friction stir welding of steels

The effects of tool geometry and properties on friction stir spot welding properties of polypropylene sheets were studied. Four different tool pin geometries, with varying pin angles, pin lengths, shoulder diameters and shoulder angles were used for friction stir spot welding. All the welding operations were done at the room temperature. Lap-shear tensile tests were carried out to find the weld static strength. Weld cross section appearance observations were also done. From the experiments the effect of tool geometry on friction stir spot weld formation and weld strength were determined. The opti- mum tool geometry for 4 mm thick polypropylene sheets were determined. The tapered cylindrical pin gave the biggest and the straight cylindrical pin gave the lowest lap-shear fracture load.

Friction stir processing (FSP) has been applied to cast aluminum alloy A356 plates to enhance the mechanical properties through microstructural refinement and homogenization. The effect of tool geometry and FSP parameters on resultant microstructure and mechanical properties was investigated. The FSP broke up and dispersed the coarse acicular Si particles creating a uniform distribution of Si particles in the aluminum matrix with significant microstructural refinement. Further, FSP healed the casting porosity. These microstructural changes led to a significant improvement in both strength and ductility. Higher tool rotation rate was the most effective parameter to refine coarse Si particles, heal the casting porosity, and consequently increase strength. The effect of tool geometry was complicated and no systematic trend was observed. For a standard pin design, maximum strength was achieved at a tool rotation rate of 900 rpm and traverse speed of 203 mm/min. Post-FSP aging increased strength for materials processed at higher tool rotation rates of 700 to 1100 rpm, but exerted only a marginal effect on samples prepared at the lower rotation rate of 300 rpm. Two-pass FSP with 100 pct overlapping passes resulted in higher strength for both as-FSP and post-FSP aged conditions.

The effect of tool geometries on the microstructure and crystallographic texture of 32-mm-thick friction stir-welded AA6082 has been investigated. The use of a tapered probe tool results in a significant variation in the grain size from the top to the base of the nugget, whereas parallel probe tools produce a uniform grain size throughout the nugget. The grain size in the nugget reflects the amount of deformation experienced and the speed of deformation expressed in terms of strain rate. An approach is proposed to calculate the strain rate during FSW of aluminum for which values between 217 and 362 s−1 were obtained. The strain rate can be either uniform or varied through the joint thickness based on the type of tool used. The tapered tool produces a variation of the strain rate, whilst the parallel tool has a uniform strain rate throughout, which can explain the obtained grain structure in each case. The tool geometries also influenced texture development with the tapered tool producing a tilt of the local shear reference frame by an angle to the normal direction equal to the taper angle.

Hard turning is increasingly adopted in the bearing industry as a cost-effective and environmentally friendly alternative to grinding. However, ensuring desired surface integrity in hardened materials remains a challenge. This study investigates the effects of tool geometry and cutting conditions on the surface integrity of 6208 deep groove ball bearing inner raceways, made from heat-treated bearing steel (58–62 HRC), commonly used in industrial applications. Three CBN inserts with different geometries—a round insert and two rhombic inserts—featuring effective rake angles of −15°, −28.5°, and −35°, were analyzed. Key metrics such as cutting forces, roundness error, surface roughness, residual stress, and white layer thickness were evaluated. It was observed that tool geometry significantly influences thermal and mechanical loads during cutting, affecting subsurface properties. The V-35 rhombic insert (35° rake angle) yielded the lowest surface roughness and roundness error, with maximum compressive residual stress of 770 MPa (hoop direction) extending to a depth of 20 µm. In contrast, the O-20 round insert produced a thicker white layer due to increased heat from larger tool–workpiece contact. Overall, the results demonstrate that insert geometry significantly affects surface integrity in hard turning, offering practical insights for optimizing bearing manufacturing processes.

Influence of tool geometry on the quality of surface produced is well known and hence any attempt to assess the performance of end milling should include the tool geometry. In the present work, experimental studies have been conducted to see the effect of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the machining performance during end milling of medium carbon steel. The first and second order mathematical models, in terms of machining parameters, were developed for surface roughness prediction using response surface methodology (RSM) on the basis of experimental results. The model selected for optimization has been validated with the Chi square test. The significance of these parameters on surface roughness has been established with analysis of variance. An attempt has also been made to optimize the surface roughness prediction model using genetic algorithms (GA). The GA program gives minimum values of surface roughness and their respective optimal conditions.

Effect of tool geometry in dissimilar Al-Steel Friction Stir Welding

The effect of tool geometry on the quality of the machined part has been an important consideration. Here the effect of tool geometry from energy minimization angle has been studied for sustainable manufacturing. The greenhouse gas (GHG) emission has been analyzed in terms of rake angle (α) and shear plane angle (φ). A numerical study of tool geometry and its effect on eco-indicators has been presented. The shear force (Fs) decreases as rake angle increases. The reduction in horse power requirement will affect the GHG emissions. It has been quantified how much CO2 is emitted in air during machining. The other toxic gases like NOx, SO2, CH4, and mercury (Hg) emissions have also been quantified. The friction force (F) declines very rapidly as rake angle (α) increases and reduce the lubricant requirement. The total specific energy (TSE) is summation of specific process energy (SPE) and specific constant energy (SCE).

Analysis of the effect of tool geometry on the cutting process of polycrystalline Fe-Cr-W alloy based on molecular dynamics simulation

Plunge milling is a critical process step in mass manufacturing of rectangular shapes in electrical connector components. These shapes are manufactured by drilling a pilot hole and subsequent plunge milling with a radial offset (pitch) one or more times. The plunged cavity serves as guidance for the final broaching cut. In light of new legislative initiatives, the electronics industry is forced to use lead-free Cu-Zn-Alloys for mass manufacturing of these connectors. The plunging tool is deflected due to the higher cutting forces experienced in machining of lead-free CuZn-alloys in comparison to alloys with lead. This results in an offset of the milled cavity and negatively impacts tool guidance in the subsequent broaching process. Therefore, the geometric tolerances cannot be met. In this paper, the effect of tool geometry and cutting parameters on the workpiece geometry in plunge milling is investigated. The effect of the microstructure of the work-piece materials CuZn37, CuZn42 and CuZn21Si3P on the tool deflection and cutting force components is examined. The tools used vary regarding the design of the corner in terms of the corner chamfer and the inner shaft thickness. Friction between chips in the tools inner flutes and the cavity walls reduced workpiece accuracy. Improvements were achieved by reducing the width of the cutting corner chamfers, using large inner flutes and applying low cutting parameters.

In this study, the effect of tool geometry on cutting forces, temperatures, pressure, heat rate and burr formation in the turning process are investigated by computational analysis. As a workpiece material, AISI 1020 steel was used, Cemented carbide was used as a cutting tool and the simulations were performed under wet cutting conditions with different tool geometry and process variables. The geometric variables (rake angle, relief angle and cutting edge radius) of the tool were changed using selected cutting parameters; thus the cutting forces, pressure, temperature and heat rate variations on the tool face were determined. The selected cutting parameters and the tools in different geometries were tested with finite element method simulation. During the tests, the cutting speed, feed, and depth of cut were kept constant and each test was conducted with a sharp uncoated tool insert. According to the results obtained, it has been observed that cutting forces and temperature gets decreased when both rake and relief angle are increased. Increased cutting edge radius causes the temperature of the tool-tip to decrease. Also, increasing the cutting edge radius causes cutting forces to increase. Cutting force components and temperature readings offered extensive data for exploring the orthogonal cutting process.KeywordsFinite element modeling simulationsTool geometryRake angleRelief angleCutting edge radius

The objective of this paper is to present a comprehensive algebraic model for better understanding of the cutting force system in the ball-end milling process. This objective is accomplished by analytically formulating the dominant dynamic components of three dimensional cutting forces in the machining of parts with helical multi-flute ball-end milling cutters. In this formulation, the effects of tool geometry, material characteristics, machining configurations, cutter-workpiece interactions, process parameters are quantitatively and explicitly presented. In this improved formulation, the axis inclination in the generation of 3-D sculpture surfaces is also incorporated to the force model, and the cutting force coefficients are predicted from the average chip thickness.