Tool Groove Research Articles

Investigation on the welded joint properties of pinless friction stir spot welding of copper under different tool grooves

Three types of pinless friction stir spot welding (PFSSW) tools were designed employing Fibonacci spiral curve, involute curve, and Archimedean spiral curve to create corresponding grooves. Subsequently, PFSSW experiments were conducted on copper sheets using these three distinct tools. The surface morphology, cross-sectional macrostructure and microstructure, microhardness, joint strength, fracture type, and fracture surface morphology of the joints were analyzed under the influence of different tools. The research findings indicate that the Fibonacci spiral curve groove (FSCG) tool exhibits the highest disparity in three-dimensional morphology within the central zone of the joint, followed by the involute curve groove (ICG) tool and the Archimedean spiral curve groove (ASCG) tool. The ICG tool generates the widest stirring zone (SZ) in the joint, while the FSCG tool produces the deepest SZ. The grains of SZ under all three tools is coarser compared to the base material. The microhardness values under the ASCG tool are relatively higher, whereas those under the FSCG tool are lower. Among the welded specimens, those created using the FSCG tool exhibit the highest average tensile-shear failure load of 8.21 kN, followed by the ICG tool of 7.80 kN, and the ASCG tool yielding the lowest average tensile-shear failure load of 7.77 kN. The fracture type of the specimens welded by FSCG tool is semi-nugget pull-out fracture, while the joint specimens of ICG tool and ASCG tool are both nugget pull-out fracture. The fracture mode of the joints under all three tools is characterized as ductile fracture. The conducted research can not only enrich the variety of PFSSW tool grooves, but also enhance the comprehension of joint properties under distinct tool groove configurations.

Effect of tool groove features on the microstructure and tensile-shear mechanical performances of probeless friction stir spot welds

Effect of tool groove features on the microstructure and tensile-shear mechanical performances of probeless friction stir spot welds

Big data-oriented wheel position and geometry calculation for cutting tool groove manufacturing based on AI algorithms

Groove is a key structure of high-performance integral cutting tools. It has to be manufactured by 5-axis grinding machine due to its complex spatial geometry and hard materials. The crucial manufacturing parameters (CMP) are grinding wheel positions and geometries. However, it is a challenging problem to solve the CMP for the designed groove. The traditional trial-and-error or analytical methods have defects such as time-consuming, limited-applying, and low accuracy. In this study, the problem is translated into a multiple output regression model of groove manufacture (MORGM) based on the big data technology and AI algorithms. The inputs are 34 groove geometry features, and the outputs are 5 CMP. Firstly, two groove machining big data sets with different range are established, each of which is includes 46,656 records. They are used as data resource for MORGM. Secondly, 7 AI algorithms, including linear regression, k nearest-neighbor regression, decision trees, random forest regression, support vector regression, and ANN algorithms, are discussed to build the model. Then, 28 experiments are carried out to test the big data set and algorithms. Finally, the best MORGM is built by ANN algorithm and the big data set with a larger range. The results show that CMP can be calculated accurately and conveniently by the built MORGM.

A compensation method for wheel wear in solid cutting tool groove grinding based on iteration algorithm

Solid cutting tool is more and more widely used, such as aerospace, automobile and 3C. Helical groove is an important feature which influences the performance of solid cutting tool. Furthermore, groove grinding is the longest and largest material removal process in whole grinding of solid tool. Therefore, the most wear of grinding wheel occurs in its grinding. The worn wheel would result in groove grinding error without a proper compensation. The traditional compensation relies on the experience of machine operator, and generally, it is performed on site. In this paper, a compensation algorithm of worn wheel is proposed by analysing the boundary contact condition which is influenced by wheel wear. Furthermore, the algorithm is implemented by using C# and validated by a set of and experiments. The experimental results show that the ground tool flutes under compensation algorithm are controlled within designed tolerances; i.e., core radius errors are 1.7% and 0.7%, rake angle errors are 1.5% and 0.6%, and edge width errors are 4.3% and 5%.

Molecular dynamic simulation of tool groove wear in nanoscale cutting of silicon

Tool wear is one of the bottlenecks that decrease the machinability of hard and brittle materials in single point diamond turning (SPDT). Specifically, a microgroove generated on the cutting edge is an important character of tool wear, which leads to the formation of subcutting edges and facilitates the ductile to brittle transition in machining. However, the mechanism of the groove wear influence on the machined workpiece, especially the subsurface damage, is not clear just by the experimental investigations. In this paper, molecular dynamic simulations were carried out to explore the influence of groove wear on workpiece subsurface damage in SPDT of single crystal silicon. The propagation of grooves was also investigated by discussion of the stress and temperature distribution on the cutting edge. The Weierstrass-Mandelbrot function was adopted to set up groove wear on the tool flank face. It is concluded that grooves improve the atomic flowing ability and the plastic deformation in the workpiece. Moreover, the grooves can also cause polycrystal transition in the workpiece subsurface. The thickness of the subsurface damaged region is increased when groove wear becomes severe. This study contributes to the understanding of the details involved in the interaction between tool groove wear and workpiece, which is advantageous to improve the machined surface quality.

Design of Helical Drills with Channels for Coolant Supply

The structure of a helical drill with a coolant channel leading to the tool groove and the rear surface is considered. SolidWorks/FlowSimulation design software is used for finite-element analysis.

Design and wear analysis of tool for high-efficiency disk milling roughing of aero-engine blisk channels

As the core component of the aero-engine, the manufacture of blisk is difficult because of its materials belonging to difficult-to-machine materials and complex structure. One of the effective ways to solve the above problems is to apply the disk milling technology to the roughing of blisk channels, and the design of disk milling tool. The optimization of cutting parameters and the research of tool wear are of great significance to the advantage of the disk milling. Firstly, based on the mutual relationship between the tool groove and the insert, the mathematical model of geometric angle influencing cutting effect is established, and the main structures of tool are calculated and modeled. Secondly, the dynamic simulation analysis of the designed disk milling tool is carried out to optimize the structure of tool by comparing the change of stress, total deformation, and main cutting force. Then, the milling experiment is carried out to optimize the cutting parameters, which are further optimized by using response surface methodology and considering the cutting efficiency. Finally, under the optimized cutting parameters, the wear condition of the designed milling tool is studied by experiment, in order to provide a better theoretical reference and technical support for the blisk high-efficiency cutting and tool design.

Experimental study of tool degradation in EDM processes: electrode material loss at the border and central zones

The analysis and optimization of tool life is an essential key to enhance the performance of EDM processes as a manufacturing technology for naval, aerospace, automotive, and other different industrial sectors. For this reason, the study of electrode degradation as a consequence of the thermal effects originated on the tool surface is of great interest to improve these material removal processes. In the present work, the degradation of electrode geometry is analyzed as a function of some process parameters such as the current intensity selected for this material removal technology and the overall depth covered by the electrode during the machining of workpiece material. This study is focused on the analysis of the mechanisms that provoke the formation of a tool groove on the frontal surface of the electrode and the average worn depth evidenced on the electrode central zone. The topology of the worn surface of the cutting tool during die-sinking EDM is analyzed, and the current intensity and penetration depth were probed to present a great influence on the tool wear. According to the results of this work, the groove depth can be adopted to describe the tool groove from the selected cutting conditions and the material profile ratio can serve to characterize the surface texture on the central zone of the electrode active surface.

Friction Stir Processing and Mechanical Testing of SiC-Al2O3 and B4C-Al2O3 Particulates Reinforced Aluminium Alloy Composites

This paper details the friction stir processing (FSP) and mechanical behaviour of hybrid composite materials. Boron carbide (B4C), silicon carbide (SiC), aluminium oxide (Al2O3) particulates are reinforced with aluminium alloy (LM25) to fabricate hybrid composite specimens via FSP. The effect of FSP parameters such as tool rotational speed, traversing speed, groove width and micro hardness was investigated. Scanning electron microscopy analysis has shown that B4C, SiC and Al2O3 particulates are dispersed well into the Aluminium alloy matrix. Mechanical test results have shown that the tensile strength and Vickers hardness of FSP aluminium alloy with B4C and Al2O3 particulates are better than FSP aluminium alloy with SiC and Al2O3 particulates.

Towards Practical Graph-Based Verification for an Object-Oriented Concurrency Model

To harness the power of multi-core and distributed platforms, and to make the development of concurrent software more accessible to software engineers, different object-oriented concurrency models such as SCOOP have been proposed. Despite the practical importance of analysing SCOOP programs, there are currently no general verification approaches that operate directly on program code without additional annotations. One reason for this is the multitude of partially conflicting semantic formalisations for SCOOP (either in theory or by-implementation). Here, we propose a simple graph transformation system (GTS) based run-time semantics for SCOOP that grasps the most common features of all known semantics of the language. This run-time model is implemented in the state-of-the-art GTS tool GROOVE, which allows us to simulate, analyse, and verify a subset of SCOOP programs with respect to deadlocks and other behavioural properties. Besides proposing the first approach to verify SCOOP programs by automatic translation to GTS, we also highlight our experiences of applying GTS (and especially GROOVE) for specifying semantics in the form of a run-time model, which should be transferable to GTS models for other concurrent languages and libraries.

The Research on Milling Force in High-Speed Milling Nickel-Based Superalloy of Inconel 718

This paper makes an experiment in high-speed milling of Inconel 718. Cutting tests were performed using round and ceramic tools, at feeds from 0.06 to 0.14 mm/tooth, Axial Depth of Cut from0.5 to 1.5mm,and cutting speeds ranging from 500 to 1037 m/min. The behaviour of the cutting forces during machining was then measure. The results show that cutting force increases first and then decreases with the increase of feed per tooth, the tool chipping and groove wear were found with the increase of axial cutting depth, and cutting force is increased; the increase in cutting force with the cutting speed increases, when the cutting speed reaches a critical speed, the cutting force as the cutting speed increases began to decline.

Modelling and analysis using GROOVE

In this paper we present case studies that describe how the graph transformation tool groove has been used to model problems from a wide variety of domains. These case studies highlight the wide applicability of groove in particular, and of graph transformation in general. They also give concrete templates for using groove in practice. Furthermore, we use the case studies to analyse the main strong and weak points of groove.

Using rule overriding to improve reusability and understandability of Dynamic Meta Modeling specifications

Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at languages based on a metamodel. A DMM specification consists of a runtime metamodel and operational rules which describe how instances of the runtime metamodel change over time. A known deficiency of the DMM approach is that it does not support the refinement of a DMM specification, e.g., in the case of defining the semantics for a refined and extended domain-specific language (DSL). Up to now, DMM specifications could only be reused by adding or removing DMM rules. In this paper, we enhance DMM such that DMM rules can override other DMM rules, similar to a method being overridden in a subclass, and we show how rule overriding can be realized with the graph transformation tool GROOVE. We argue that rule overriding does not only have positive impact on reusability, but also improves the intuitive understandability of DMM semantics specifications.

Characteristics of “dynamic hard particles” in nanoscale ductile mode cutting of monocrystalline silicon with diamond tools in relation to tool groove wear

In nanoscale ductile mode cutting of the monocrystalline silicon wafer, micro/nano groove wear on the diamond cutting tool flank face is often observed, which is beyond the understanding based on conventional cutting processes because the silicon workpiece material is monocrystalline with the hardness lower than that of the diamond cutting tool at room temperature. From the investigation of such a phenomenon, a concept of “dynamic hard particles” generated in the chip formation zone as a result of silicon phase transformation from monocrystalline to amorphous was proposed. It was believed that the “dynamic hard particles” caused the groove wear at the tool flank. In this study, the characteristics of such “dynamic hard particles” and their relationship with the diamond tool groove wear have been investigated through molecular dynamics (MD) simulation of nanoscale ductile mode cutting of monocrystalline silicon with diamond tools. The results show that during the cutting process, due to the workpiece material phase transformation from monocrystalline to amorphous, which results in the existence of silicon atom groups with shorter bond lengths in the chip formation zone, “dynamic hard particles” having a dynamic and uneven distribution over the entire chip formation zone are formed. The distribution changes over time and cutting stages. When the cutting runs into a steady state, the “dynamic hard particles” are mostly distributed in the lower portion of chip formation zone, contributing directly to three body abrasions on the tool flank face, causing groove wear at tool flank. The dynamic distribution of the “dynamic hard particles” also causes the uncertainty of the groove wear locations at the tool flank.

Double-CCD Stereoscopic Vision System Monitoring Chip Shape

With the continuous development and popularity of optical sensor and computer vision, machining process monitoring based on CCD camera has attracted more and more attention in recent years. Aiming at detecting the shape of cutting chip forming in cylindrical turning, a special matching algorithm is presented in this paper. As a reliable measuring method of chip shape parameter doesn’t exist, this algorithm can hardly be verified in a precise manner, however comparison between experimental results and the original images shows that this matching algorithm is effective. A double-CCD stereoscopic vision monitoring system employing this algorithm can be used to estimate the wearing and breakage of tool, and provide significant instruction for the design of tool groove for its capability of in-process measuring chip shape.