Characteristic of the wear of a tool coating based on amorphous carbon during chipboard milling

2020 ◽  
Vol 111 ◽  
pp. 53-59
Author(s):  
Paweł Czarniak ◽  
Karol Szymanowski ◽  
Peter Panjan

Characteristic of the wear of a tool coating based on amorphous carbon during chipboard milling. The study verified the durability and the course of wear during the durability tests of the TiAlN / a-C:N double tool coating. The aforementioned coating consisted of a bottom layer of TiAlN and a top layer based on nitrogenenriched amorphous carbon. Standard replaceable cutters for milling heads made of WC-Co sintered carbide were subjected to the modification process. The coating was applied using plasma by RF Magnetron Sputtering. During the tests, the blade wear was measured using a workshop microscope. The VB max indicator measured on the clearance face was adopted as the blunting criterion and its maximum value was set on 0,2 mm. The results show that the additional coating of amorphous carbon contributed to the increase of the tool durability determined with cutting distance. The use of only a single layer based on TiAlN shortened the durability by about 3%. On the other hand, applying both the bottom and top layers TiAlN /a-C:N) extended the cutting distance by about 24%. The research showed a clear advantage in terms of the durability of the blades modified with a multi-layer coating in relation to a single-layer. Moreover, the positive effect of the top layer containing amorphous carbon on tool durability has been demonstrated.

2021 ◽  
pp. 004051752199434
Author(s):  
Yuanjun Liu ◽  
Yanfeng Yang

Coating is a commonly used process for the preparation of protective textiles. In this study, the absorbing coated composite material was prepared by a coating process, using plain weave polyester/cotton fabric as the base fabric, PU-2540 polyurethane as the binder, and graphite, bismuth and bismuth oxide as the functional particles. The effects of the content of functional particles and the ratio of functional particles on the dielectric constant, reflection loss, shielding effectiveness, and tensile strength of the single-layer coating composites were studied using the control variable method. The results showed that when the frequency was 1–1000 MHz, the real and imaginary parts of the dielectric constant, the tangential value of the loss angle, and the tensile value increased with the increase of the coating content, and the polarization, loss and attenuation property, and mechanical property of the electromagnetic wave were enhanced. When graphite, bismuth, and bismuth oxide was mixed at the ratio of 9:0:0 in weight, the polarization property was the best. When mixed at the ratio of 6:1:2 in weight, the loss performance and attenuation ability were the best. When mixed at the ratio of 6:3:0 in weight, the absorbing property and mechanical property were the best. When mixed at the ratio of 6:2:1 in weight, the shielding property was the best.


2013 ◽  
Vol 587 ◽  
pp. 245-248 ◽  
Author(s):  
Le Ping Yan ◽  
Joaquim Miguel Oliveira ◽  
Ana L. Oliveira ◽  
Rui L. Reis

In this study, bilayered silk and silk/nanoCaP scaffolds were developed for osteochondral tissue engineering. Aqueous silk solution (16 wt.%) was used for preparation of the cartilage-like layer and, for generation of the silk/nanoCaP suspension and the bottom layer (CaP/Silk: 16 wt.%). The scaffolds were formed by using salt-leaching/lyophilization approach. The scanning electron microscopy revealed that the both layers presented porous structure and integrated well. Micro-computed tomography images confirmed that the CaP phase was only retained in the silk/nanoCaP layer. The hydration degree and mechanical properties of the bilayered scaffold were comparable to the ones of each single layer. The apatite crystal formation was limited to the silk/nanoCaP layer, when soaking the scaffold in a simulated body fluid solution, which is a must for the application of the developed scaffolds in OC tissue engineering.


2020 ◽  
Vol 112 ◽  
pp. 54-59
Author(s):  
Paweł Czarniak ◽  
Karol Szymanowski ◽  
Peter Panjan

Influence of the microstructure of tool coatings based on Ti and Al on the blunting process during chipboard processing.This work concerns three different tool coatings containing Ti and Al. i.e. TiN, AlTiN, TiAlSiN applied to cutting tools used in the machining of wood materials. In the case of the AlTiN coating, a multilayer structure with alternately arranged AlTiN and TiN nano-layers was used. The above coatings were applied to standard replaceable knives used for CNC milling heads made of WC-Co cemented carbide. The deposition process was carried out using the RF Magnetron Sputtering method. During the measurement on a workshop microscope, the VBmax index measured on the clearance face was adopted as the wear criterion. The research proved a very good behaviour of the TiN/AlTiN multilayer coating, for which the longest average service life which was recorded exceeded the results obtained for the reference tool by about 30%. The addition of silicon, which was supposed to increase the abrasion resistance, only did not improve the durability of the blade, it actually worsened it by 6%. In addition, the coating, which has been widely used in the machine industry for a very long time, i.e. TiN, did not extend the tool life significantly (+ 7%).


Author(s):  
Sarbjeet Kaushal ◽  
Dheeraj Gupta ◽  
Hiralal Bhowmick

In this study, functional performance of Ni/Cr3C2 functionally graded claddings (FGCs) was investigated under dry sliding wear environment. The Ni/Cr3C2-based FGCs were produced by varying Cr3C2 fraction (Ni-XCr3C2) (X=10%–30% by weight) using microwave irradiation. The FGC layers were composed of cellular-structure with reinforced particles dispersed randomly inside Ni-based matrix. Variation of Cr3C2 particles inside Ni matrix exhibited significant impact on micro-structural and mechanical properties. The microhardness profile of the FGC layers showed an increase in hardness value with an increase in the amount of reinforced Cr3C2 particles. FGC top layers showed the maximum value of micro-hardness of 555 ± 34 HV. Functional performance of microwave processed FGCs was studied through the pin-on-disk tribometer under varying sliding velocity and sliding distances. For comprehension study, wear study was also carried out on microwave processed single layer clads with compositions corresponding to FGC layers. The FGC sample showed better wear resistance than all single clad layers and substrate material. The FGC sample exhibited 1.6 times less wear rate than the Ni-based + 30% Cr3C2 single layer clad. The worn-out surfaces of FGC and single-layer-clads showed presence of multiples cracks and grooves, which resulted in their weight loss during dry sliding contact. Material debonding and the formation of craters and cracks are the main phenomena responsible for the wear loss in the FGC surface.


2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     


2018 ◽  
Vol 8 (7) ◽  
pp. 1127 ◽  
Author(s):  
Chongsei Yoon ◽  
Buil Jeon ◽  
Giwan Yoon

In this paper, we present a study of various ZnO/SiO2-stacked thin film structures for flexible micro-energy harvesting devices. Two groups of micro-energy harvesting devices, SiO2/ZnO/SiO2 micro-energy generators (SZS-MGs) and ZnO/SiO2/ZnO micro-energy generators (ZSZ-MGs), were fabricated by stacking both SiO2 and ZnO thin films, and the resulting devices were characterized. With a particular interest in the fabrication of flexible devices, all the ZnO and SiO2 thin films were deposited on indium tin oxide (ITO)-coated polyethylene naphthalate (PEN) substrates using a radio frequency (RF) magnetron sputtering technique. The effects of the thickness and/or position of the SiO2 films on the device performance were investigated by observing the variations of output voltage in comparison with that of a control sample. As a result, compared to the ZnO single-layer device, all the ZSZ-MGs showed much better output voltages, while all the SZS-MG showed only slightly better output voltages. Among the ZSZ-MGs, the highest output voltages were obtained from the ZSZ-MGs where the SiO2 thin films were deposited using a deposition power of 150 W. Overall, the device performance seems to depend significantly on the position as well as the thickness of the SiO2 thin films in the ZnO/SiO2-stacked multilayer structures, in addition to the processing conditions.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Minghua Li ◽  
Hui Shen ◽  
Lin Zhuang ◽  
Daming Chen ◽  
Xinghua Liang

In this work we prepared double-layer antireflection coatings (DARC) by using the SiO2/SiNx:H heterostructure design. SiO2thin films were deposited by electron-beam evaporation on the conventional solar cell with SiNx:H single-layer antireflection coatings (SARC), while to avoid the coverage of SiO2on the front side busbars, a steel mask was utilized as the shelter. The thickness of the SiNx:H as bottom layer was fixed at 80 nm, and the varied thicknesses of the SiO2as top layer were 105 nm and 122 nm. The results show that the SiO2/SiNx:H DARC have a much lower reflectance and higher external quantum efficiency (EQE) in short wavelengths compared with the SiNx:H SARC. A higher energy conversion efficiency of 17.80% was obtained for solar cells with SiO2(105 nm)/SiNx:H (80 nm) DARC, an absolute conversion efficiency increase of 0.32% compared with the conventional single SiNx:H-coated cells.


2017 ◽  
Vol 868 ◽  
pp. 139-150
Author(s):  
Zhi Xiang Xu ◽  
Hai Yang Guo

Based on thermo-elastic regime, ultrasound can be generated by modulated laser pulse. When laser-generated ultrasound technology is applied to measure the thickness of coating and study the coating characters, even analysis the effects of coating during detecting the cracks and voids of the substrate, it is shown that it’s a very efficiency technology. When measuring the coating thickness, it can control the accuracy scope at the nanoscale; the relative error is under 2% for single layer coating, under 10% for double layer coating. As to coating characters, for example, Young modulus, Poisson's ratio etc, according to BP Neural network algorithm, use the nonlinear map relationship between material parameter and laser generated ultrasound wave forms to get these coating characters reversal. Studying the dispersion characteristic of the coating-substrate system can analysis effects of coating to defects detecting that coating absorbs large energy which leads to faster heat conduction speed than uncoated sample, but have smaller surface wave amplitude. All these are shown that laser-generated ultrasound technology can realize high-precise measurement and have an extensive use in the field of nondestructive testing.


2020 ◽  
Vol 984 ◽  
pp. 177-182
Author(s):  
Meng Lei Zhou ◽  
Li Na Zhang ◽  
Yang Liu ◽  
Feng Qiang Nan

In order to obtain better quality and mechanical performances, the coating process of super-porous propellants was optimized. The mechanical performances of super-porous propellants were tested, under some conditions with different temperatures, different numbers of cladding layers, different thicknesses of the cladding layer and different ratios of inner and outer layers, through many different analytical methods including impact test, interrupted-burning test and three-dimensional video observation test. The results show that the mechanical performances of super-porous propellants are positively correlated with the temperature, the coating thickness and the ratio of the outer layer. The double-layer coating also can obtain better coating effect than the single-layer coating.


2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Rinku K. Mittal ◽  
Salil S. Kulkarni ◽  
Harish Barshilia ◽  
Ramesh Singh

Abstract Micromilling process is widely used to create complex 3D miniature products due to its flexibility and its ability to process difficult-to-cut material like Titanium alloys. High rotational speeds are used to overcome the limited flexural stiffness of the tool but the cutting zone temperatures rise due to the high rotational speeds. In addition to this, friction between the tool workpiece and tool chip also plays a major role in the temperature rise. The friction and temperature affect the cutting forces, tool life and stability of the process. To reduce the friction and heat generation, nanostructured solid lubricant coatings can be used. This study is focused on characterizing the effect of amorphous carbon (WC/a-C) coating on the micromachining response during high-speed micromilling of Ti–6Al–4V. A decrease in cutting forces for coated tools is observed for lower feed. A comprehensive tool coating damage assessment has been done in terms of debonding area on flank and rake faces. An increase in debonding area has been observed with lengths of cut but at a feed/flute of 4 μm, tool breakage occurs after a machining length of 60 mm.


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