scholarly journals Performance of Volcano-Like Laser Textured Cutting Tools: An Experimental and Simulative Investigation

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 98 ◽  
Author(s):  
Zhengyang Kang ◽  
Yonghong Fu ◽  
Xingyu Fu ◽  
Martin Jun

In recent years, surface texturing in micro-scale has been attempted on the surface of cutting tools for multiple purposes, e.g., cutting force reduction, prolonging life-span, anti-adhesion, etc. With respect to machinability and performance, micro-groove texture (MGT) has dominated in this field compared to other textured patterns. In this study, a novel volcano-like texture (VLT) was fabricated on the rake face of cemented carbide inserts (WC-Co, YG6) by fiber laser. The following cutting experiment tested the flat, MGT and VLT tools in turning aluminum alloy 6061. The effects of coolant and cutting conditions were investigated. In addition, a validated FEM model was employed to explore the distribution of stress and temperature fields in the tool-chip interface. The initial forming process of adhesion layer on rake face was investigated as well. The results indicated that lower cutting force and less adhesion can be achieved by small scale VLT. This study not only introduced VLT on cutting tools but also revealed its comprehensive performance.

2020 ◽  
Vol 14 (5-6) ◽  
pp. 733-742
Author(s):  
S. Böhm ◽  
A. Ahsan ◽  
J. Kröger ◽  
J. Witte

AbstractIn recent years surface texturing of the cutting tools has proved to improve tribological characteristics at tool/chip and tool/workpiece interface and help to reduce cutting and feed forces as well as tool wear. Most, if not all, of the studies have focused on subtractively made textures whereby the material is removed from the surface. This study investigates the performance of additively made surface structures whereby hard ceramic particles are dispersed in the form of dome shaped textures on the surface of the cutting tools using solid state millisecond pulsed laser (pulsed laser implantation). Dry cutting tests were performed on ductile cast iron. The results show a greater reduction of process forces with implantation of flank face as compared to rake face. Both cutting and feed forces were reduced by 10% compared to the non-structured tool. In addition, the tool life increased by a factor of 3 whereas the average flank wear reduced by as much as 80% and cutting edge rounding by up to 60%.


Author(s):  
J. Ma ◽  
Xianchen Ge ◽  
Nick H. Duong ◽  
Shuting Lei

This paper studies the performance of restricted cutting tool in dry orthogonal machining of mild steel (AISI 1045 steel) using finite element simulations. The rake face of cemented carbide (WC/Co) cutting inserts is designed and the rake face length is shortened. The purpose is to examine the effect of shortened tools on machining performance and to compare it with regular cutting tools. The following restricted tool parameters are examined: length of rake face, alpha angle (the angle between the rake face and the supporting face), and edge radius. Their effects are assessed in terms of the main force, thrust force, and chip-tool contact length. It is found that restricted cutting tools generate lower cutting force and thrust force and consequently lower the energy necessary for machining. The length of rake face, the angle between the rake face and the supporting face, and edge radius all have influence on cutting force in their own ways. The effects of these three parameters on the tool temperature distribution are also investigated.


Author(s):  
Han Wu ◽  
Nick H. Duong ◽  
J. Ma ◽  
Shuting Lei

In this paper, the commercial FEM software package Abaqus is used to investigate the effects of microgrooved cutting tools in high speed orthogonal cutting of AISI 1045 steel. Microgrooves are designed and fabricated on the rake face of cemented carbide (WC/Co) cutting inserts. A coupled Eulerian-Lagrangian (CEL) finite element model is developed based on Abaqus to solve the evolution of the cutting temperature, chip morphology, cutting force, and phase constitutes simultaneously. This model is validated by comparing the numerical results with the experimental data for orthogonal high speed cutting of AISI 1045 steel with various cutting conditions. In addition, this model is also validated by comparing with the experimental data of regular tool and microgrooved cutting tool under the cutting speed of 120m/min. This validated CEL FEM model is then utilized to investigate the effects of microgrooved cutting tools on the phase transformation, cutting force, cutting temperature, and chip morphology in high speed orthogonal cutting of AISI 1045. The effects of microgroove width, edge distance (the distance from cutting edge to the first microgroove), and microgroove depth are examined and assessed in terms of cutting force, cutting temperature, chip morphology, and phase transformation. It is found that this CEL FEM model can capture the essential features of orthogonal high speed cutting of AISI 1045 using microgrooved cutting tools. It is also concluded that microgrooved cutting tools can not effectively reduce the cutting force in high speed machining, which is contrary to the conclusion obtained for low speed machining in previous research. However, microgrooves on the rake face have influence on the austenite percentage in the chip near the rake face. This research provides insightful guidance for optimizing the cutting performance in terms of cutting temperature, cutting force, chip morphology, and phase transformation in high speed machining of AISI 1045 steel.


2016 ◽  
Vol 693 ◽  
pp. 697-703
Author(s):  
Bin Wang ◽  
Jia Yang Zhang ◽  
Chun Ling Wu ◽  
Wen Jun Deng

Micro textures on the tool rake face facilitate to improve friction conditions at the tool-chip interface, and therefore contribute to decreasing cutting force and cutting temperature. Literature has shown that lateral textures (perpendicular to chip flow direction) on tool rake face have better performance than other texture patterns. In this present study, the effect of different lateral micro textures on cutting force, cutting temperature and chip formation were analyzed via an advanced finite element analysis code in rectangular groove cutting processes. Three cutting tools with different lateral micro textures on tool rake face, one is parallel textured (MT1) and two are non-parallel textured (MT2, MT3), were employed in this study. The results indicate that lateral textured tools have significant advantages in terms of controlling chip curl, reducing cutting forces and decreasing cutting temperature. Synthetically, asymmetrical lateral textured tool MT2 show best performance in chip breakability control, decreasing cutting forces, and lower mean cutting temperature along the main cutting edge.


Author(s):  
Zhengyang Kang ◽  
Martin Byung-Guk Jun ◽  
Yonghong Fu

Recently, surface nano/micro morphologies have been applied on cutting tools for multiple purposes, such as cutting force reduction and life-span prolonging. In this study, the micro-grooves texture (MGT) and volcano-like texture (VLT) were patterned on cemented carbide (WC-Co, YG6) cutting inserts’ rake faces by YAG and fiber laser systems. The effects of laser pulse width and energy on texture dimensions were investigated, followed by the micro hardness, EDX and metallographic analyses providing detailed information for VLT’s properties and forming process. The subsequent cutting experiment tested the flat, MGT and VLT tools in turning aluminum alloy 6061 with considering the following factors: textured scale and density, coolant, cutting speed and machining type (rough or finish). VLT tools showed lower cutting forces in rough cutting, and poor compatibility to cutting coolant; MGT improves the efficiency of coolant usage. This study not only introduced VLT to cutting tools, but also revealed its comprehensive performances.


2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3432
Author(s):  
Edwin Gevorkyan ◽  
Mirosław Rucki ◽  
Tadeusz Sałaciński ◽  
Zbigniew Siemiątkowski ◽  
Volodymyr Nerubatskyi ◽  
...  

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, vc = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of vc = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 802
Author(s):  
Suye Li ◽  
Hengqian Wu ◽  
Yanna Zhao ◽  
Ruiyan Zhang ◽  
Zhengping Wang ◽  
...  

The quality control of drug products during manufacturing processes is important, particularly the presence of different polymorphic forms in active pharmaceutical ingredients (APIs) during production, which could affect the performance of the formulated products. The objective of this study was to investigate the phase transformation of fexofenadine hydrochloride (FXD) and its influence on the quality and performance of the drug. Water addition was key controlling factor for the polymorphic conversion from Form I to Form II (hydrate) during the wet granulation process of FXD. Water-induced phase transformation of FXD was studied and quantified with XRD and thermal analysis. When FXD was mixed with water, it rapidly converted to Form II, while the conversion is retarded when FXD is formulated with excipients. In addition, the conversion was totally inhibited when the water content was <15% w/w. The relationship between phase transformation and water content was studied at the small scale, and it was also applicable for the scale-up during wet granulation. The effect of phase transition on the FXD tablet performance was investigated by evaluating granule characterization and dissolution behavior. It was shown that, during the transition, the dissolved FXD acted as a binder to improve the properties of granules, such as density and flowability. However, if the water was over added, it can lead to the incomplete release of the FXD during dissolution. In order to balance the quality attributes and the dissolution of granules, the phase transition of FXD and the water amount added should be controlled during wet granulation.


2015 ◽  
Vol 764 ◽  
pp. 362-394 ◽  
Author(s):  
T. Dairay ◽  
V. Fortuné ◽  
E. Lamballais ◽  
L.-E. Brizzi

AbstractDirect numerical simulation (DNS) of an impinging jet flow with a nozzle-to-plate distance of two jet diameters and a Reynolds number of 10 000 is carried out at high spatial resolution using high-order numerical methods. The flow configuration is designed to enable the development of a fully turbulent regime with the appearance of a well-marked secondary maximum in the radial distribution of the mean heat transfer. The velocity and temperature statistics are validated with documented experiments. The DNS database is then analysed focusing on the role of unsteady processes to explain the spatial distribution of the heat transfer coefficient at the wall. A phenomenological scenario is proposed on the basis of instantaneous flow visualisations in order to explain the non-monotonic radial evolution of the Nusselt number in the stagnation region. This scenario is then assessed by analysing the wall temperature and the wall shear stress distributions and also through the use of conditional averaging of velocity and temperature fields. On one hand, the heat transfer is primarily driven by the large-scale toroidal primary and secondary vortices emitted periodically. On the other hand, these vortices are subjected to azimuthal distortions associated with the production of radially elongated structures at small scale. These distortions are responsible for the appearance of very high heat transfer zones organised as cold fluid spots on the heated wall. These cold spots are shaped by the radial structures through a filament propagation of the heat transfer. The analysis of probability density functions shows that these strong events are highly intermittent in time and space while contributing essentially to the secondary peak observed in the radial evolution of the Nusselt number.


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