scholarly journals Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

Author(s):  
Lukas Seeholzer ◽  
Stefan Süssmaier ◽  
Fabian Kneubühler ◽  
Konrad Wegener

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 75
Author(s):  
Nikolaos E. Karkalos ◽  
Panagiotis Karmiris-Obratański ◽  
Szymon Kurpiel ◽  
Krzysztof Zagórski ◽  
Angelos P. Markopoulos

Surface quality has always been an important goal in the manufacturing industry, as it is not only related to the achievement of appropriate geometrical tolerances but also plays an important role in the tribological behavior of the surface as well as its resistance to fatigue and corrosion. Usually, in order to achieve sufficiently high surface quality, process parameters, such as cutting speed and feed, are regulated or special types of cutting tools are used. In the present work, an alternative strategy for slot milling is adopted, namely, trochoidal milling, which employs a more complex trajectory for the cutting tool. Two series of experiments were initially conducted with traditional and trochoidal milling under various feed and cutting speed values in order to evaluate the capabilities of trochoidal milling. The findings showed a clear difference between the two milling strategies, and it was shown that the trochoidal milling strategy is able to provide superior surface quality when the appropriate process parameters are also chosen. Finally, the effect of the depth of cut, coolant and trochoidal stepover on surface roughness during trochoidal milling was also investigated, and it was found that lower depths of cut, the use of coolant and low values of trochoidal stepover can lead to a considerable decrease in surface roughness.


2017 ◽  
Vol 36 (3) ◽  
pp. 151-166 ◽  
Author(s):  
Christian Hopmann ◽  
Nicolai Lammert ◽  
Yuxiao Zhang

Thermoplastic foam injection moulding offers various advantages for both processing and product design. Despite its many benefits, the moderate surface quality still constitutes a major disadvantage of this process. The mould temperature can be controlled dynamically to improve the surface quality. Different dynamic temperature control strategies are employed and analysed regarding their effectiveness and scope of application. Mould temperatures above the specific material transition temperatures allow the surface defects to be cured and enable the production of foamed thermoplastic parts with surface qualities comparable to those of the compact reference samples. The high mould temperatures during the injection phase alter the foam structure and the skin layer thicknesses, which impacts the mechanical properties.


Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 325
Author(s):  
Muslim Mahardika ◽  
Martin Andre Setyawan ◽  
Tutik Sriani ◽  
Norihisa Miki ◽  
Gunawan Setia Prihandana

Titanium is widely used in biomedical components. As a promising advanced manufacturing process, electropolishing (EP) has advantages in polishing the machined surfaces of material that is hard and difficult to cut. This paper presents the fabrication of a titanium microchannel using the EP process. The Taguchi method was adopted to determine the optimal process parameters by which to obtain high surface quality using an L9 orthogonal array. The Pareto analysis of variance was utilized to analyze the three machining process parameters: applied voltage, concentration of ethanol in an electrolyte solution, and machining gap. In vitro experiments were conducted to investigate the fouling effect of blood on the microchannel. The result shows that an applied voltage of 20 V, an ethanol concentration of 20 vol.%, and a machining gap of 10 mm are the optimum machining parameters by which to enhance the surface quality of a titanium microchannel. Under the optimized machining parameters, the surface quality improved from 1.46 to 0.22 μm. Moreover, the adhesion of blood on the surface during the fouling experiment was significantly decreased, thus confirming the effectiveness of the proposed method.


2014 ◽  
Vol 1018 ◽  
pp. 269-276
Author(s):  
Andrea Reiß ◽  
Ulf Engel

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.


2013 ◽  
Vol 581 ◽  
pp. 211-216 ◽  
Author(s):  
Jiří Čop ◽  
Imrich Lukovics

This research paper focuses on grinding of materials used for tools (100Cr6 (CSN 4 14109), X210Cr12 ( CSN 4 19436) and epoxy resin) using grinding wheels from cubic boron nitride and diamond. The disadvantage of grinding of difficult-to-machine materials is higher wear of grinding wheels. The modern grinding wheels are able to achieve high accuracy of dimensions and high surface quality with a smaller wear of grinding wheels then grinding wheels from conventional materials. Correctly selected technological conditions are one of the most important matters to achieve the required surface quality. The main aim of this research is to determine the influence of technological conditions to quality of surface after planar grinding. The research determines the influence of the grain type of grinding wheels, feed rate and cutting depth on the quality of functional surfaces.


2020 ◽  
Vol 45 (23) ◽  
pp. 6438
Author(s):  
Yingying Zhang ◽  
Rongguang Liang ◽  
Oliver Joshua Spires ◽  
Shaohui Yin ◽  
Allen Yi ◽  
...  

2010 ◽  
Vol 458 ◽  
pp. 307-312 ◽  
Author(s):  
Yi Quan Yu ◽  
Jian She Zhao ◽  
Bing Hui Li ◽  
Jia Wen Xu

For the difficulties of machining small hole on difficult-to-cut materials, a study of hole-making technology by pulsed electrolyte jet machining is carried out. Main effects of DC power and pulse power on the hole conicity, surface quality and drilling efficiency are studied in this paper. The experiment results show that: hole with high surface quality can be available and the hole conicity is effectively reduced by using pulsed electrolyte jet machining; DC is suitable for improving efficiency when the ECM voltage is less than 300V, while pulse power supply shall be adopted to achieve good surface quality and high drilling efficiency when the ECM voltage is more than 300V.


2009 ◽  
Vol 69-70 ◽  
pp. 113-117
Author(s):  
Qian Fa Deng ◽  
Dong Hui Wen ◽  
Feng Chen ◽  
Li Tao ◽  
Ju Long Yuan

To obtain high surface quality and high finishing efficiency in machining SUS440 stainless steel, a novel machining technology employing a semi-fixed abrasive plate (SFAP) is adopted. The SFAP is developed for preventing lapped surface from damage caused by larger particles (from grain size dispersion or from outside of processing area, larger particles could bring uneven load distribution on processing region). The effects of different parameters on the surface quality and the material removal rate (MRR) of SUS440 stainless steel which is lapped by SFAP are investigated in this paper. The control parameters of the lapping process include the lapping time, the load, the rotating speed of the lapping plate, and etc. SFAP of 800# SiC abrasive used, Experimental results indicate that SFAP can avoid the large scratch effectively and the surface roughness (Ra) of the workpiece could be improved from 250 nm to 50 nm in 12 Min. A nearly mirror-like surface can be obtained.


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