Providing of Operational Properties for Gas-Turbine Engine Parts and Assemblies Using Electrospark Deposition

2020 ◽  
Vol 992 ◽  
pp. 574-579
Author(s):  
L.V. Denisov ◽  
A.G. Boytsov ◽  
M.V. Siluyanova

Article explains manufacturing capability of titanium parts reliability enhancement and life cycle enhancement by electrospark deposition using low energy discharges. Carbon electrodes used to form functional properties of parts surface layer. Alloyed carbooxide zone consist of highly dispersed structure (with particles of titanium carbide, titanium oxide, graphite), with 3-10 micron thick, and high hardness antifrictionality. Alloyed layer contain ordered phase Ti8C5, TiC, and the structure of Ti6C3,75. Parts dimensions almost do not changed after electrospark deposition with carbon electrodes. Subsequent diamond burnishing decrease friction coefficient and surface roughness. Fatigue resistance increased after healing of defects and microcracks. Local carbooxidation and burnishing used to increase wear resistance of titanium alloys.

2020 ◽  
pp. 99-104
Author(s):  
S.A. Zaydes ◽  
A.N. Mashukov ◽  
T.Ya. Druzhinina

The contact belt of the gate assembly is the main part of high pressure fittings. The serviceability of the fittings assembly as whole depends on the air-tightness and quality of the mating surfaces. The technology of diamond burnishing allows to increase the interface of the nodes by red ucing the surface roughness of the metal-to-metal seal. The real experience for improving of the fittings contact belt due to the use of diamond burnishing of the nozzles seats and the conical surface of the rods.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 951
Author(s):  
Tomáš Primus ◽  
Josef Hlavinka ◽  
Pavel Zeman ◽  
Jan Brajer ◽  
Martin Šorm ◽  
...  

The lifetime and properties of cutting tools and forming moulds can be prolonged and enhanced by the deposition of hard, thin coatings. After a certain period of usage, the coating will deteriorate. Any remaining coating must be removed prior to successful recoating. Laser stripping is a fast and environmentally friendly coating removal method. In this paper, we present laser removal of two types of coatings deposited on a 1.2379 tool steel substrate, namely, an AlTiN coating with high hardness and a DLC C coating with a small coefficient of friction (COF). A powerful nanosecond laser was employed to remove the coating from the substrate with high efficiency, along with suitable residual surface roughness. Measurements were taken of surface roughness, removed depth, and working time on a stripped area of 1 cm2. The samples were evaluated under a microscope, with a 3D profilometer, and by EDS chemical analysis. Successful removal of the coating was confirmed by optical analysis, but detailed chemical characterisation showed that about 30% of the coating element may remain on the surface. Moreover, a working time of less than 7.5 s per cm2 was obtained in this study. In addition, it was shown that the application of a second low energy, high frequency laser beam pass leads to remelting of the peaks of the material and reduced surface roughness.


2003 ◽  
Vol 10 (06) ◽  
pp. 837-841
Author(s):  
M. XU ◽  
C. TEICHERT

With tips of different hardness, we analyzed the effect of the hardness and shape of the actual AFM tip on the measurement of the best GaSb quantum dot (QD) structures induced by low energy Ar + sputtering. The comparison indicated that the complete information on the detailed dot shape and order structure can be determined with the hard and good tip, while with the soft or worn tip some information on the dot height and shape cannot be obtained. Our results suggest that, in order to obtain the complete surface information, the high hardness and good AFM tip should be used for semiconductor QD structures.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771061 ◽  
Author(s):  
Duc Tran Minh ◽  
Long Tran The ◽  
Ngoc Tran Bao

In this article, an attempt has been made to explore the potential performance of Al2O3 nanoparticle–based cutting fluid in hard milling of hardened 60Si2Mn steel (50-52 HRC) under different minimum quantity lubrication conditions. The comparison of hard milling under minimum quantity lubrication conditions is done between pure cutting fluids and nanofluids (in terms of surface roughness, cutting force, tool wear, and tool life). Hard milling under minimum quantity lubrication conditions with nanofluid Al2O3 of 0.5% volume has shown superior results. The improvement in tool life almost 177%–230% (depending on the type of nanofluid) and the reduction in surface roughness and cutting forces almost 35%–60% have been observed under minimum quantity lubrication with Al2O3 nanofluids due to better tribological behavior as well as cooling and lubricating effects. The most outstanding result is that the uncoated cemented carbide insert can be effectively used in machining high-hardness steels (>50 HRC) while maintaining long tool life and good surface integrity (Ra = 0.08–0.35 µm; Rz = 0.5–2.0 µm, equivalent to finish grinding) rather than using the costlier tools like coated carbide, ceramic, and (P)CBN. Therefore, using hard nanoparticle–reinforced cutting fluid under minimum quantity lubrication conditions in practical manufacturing becomes very promising.


2009 ◽  
Vol 86 (4-6) ◽  
pp. 497-499 ◽  
Author(s):  
Takuro Inaba ◽  
Yuichi Kurashima ◽  
Shahjada A. Pahlovy ◽  
Iwao Miyamoto ◽  
Manabu Ando ◽  
...  

1994 ◽  
Vol 367 ◽  
Author(s):  
P.O. Pettersson ◽  
R.J. Miles ◽  
T.C. Mcgill

AbstractWe present the results of electron beam assisted molecular beam epitaxy (EB-MBE) on the growth mode of silicon on CaF2/Si(111). By irradiating the CaF2 surface with low energy electrons, the fluorine is desorbed, leaving an ordered array of F-centers behind. Using atomic force microscopy (AFM), we do not detect any surface damage on the CaF2 layer due to the low energy electron irradiation. The surface free energy of the CaF2 is raised due to the F-center array and the subsequent silicon layer is smoother. Using AFM and X-ray photoelectron spectroscopy (XPS), we find an optimal range of exposures for high temperature (650°C) growth of the silicon overlayer that minimizes surface roughness of the silicon overlayer and we present a simple model based on geometrical thermodynamics to explain this.We observed a similar optimal range of exposures that minimizes the surface roughness for medium (575°C) and low (500°C) growth temperatures of the silicon layer. We present an explanation for this growth mode based on kinetics.


2019 ◽  
Vol 968 ◽  
pp. 131-142 ◽  
Author(s):  
Viacheslav Tarelnyk ◽  
Ievgen Konoplianchenko ◽  
Nataliia Tarelnyk ◽  
Aleksey Kozachenko

The paper represents a formalized methodology for solving the problem of creating fundamentally new materials, such as "base - coating" ones, which have increased surface wear resistance and relatively high strength and viscosity. Electrospark alloying (ESA) method is proposed as a process for depositing protective coatings on metal surfaces. There are considered the issues of improving the quality of the coatings formed by the ESA method. There is specified a feature of processing the surfaces having been treated with the use of the ESA method, which feature being associated with a relatively small thickness of the layers formed (tens of micrometers). Since to reduce the roughness of the surface, the process of grinding is difficult or even unacceptable to perform, it has been suggested to use the method of surface plastic deformation (SPD). One of the effective SPD methods for finishing the parts is a diamond smoothing process, which, in contrast to running-in with a ball or roller, allows processing the parts of very high hardness values. As a reserve to improve the quality of coatings formed by the ESA method, there is considered a process for producing combined electrospark deposition coatings (CEC) with hard wear-resistant and soft anti-friction metals integrated therein. There are represented the results of mass transfer process investigation performed at forming the CEC on the specimens of steel 45 with indium, tin and copper being used as soft antifriction metals, and tungsten and hard alloy of VK8 grade applied as wear-resistant materials. There is represented a mathematical model for calculating the main ESA technological parameters being necessary for forming the CEC and allowing to predict the weight gain (increase in weight) and size gain (increase in size) at the cathode (the part). It allows predicting the CEC main technological parameters for any electrode pair materials (substrate material and electrode materials making up the CEC).


2012 ◽  
Vol 468-471 ◽  
pp. 1560-1563 ◽  
Author(s):  
Ji Cai Kuai ◽  
Fei Hu Zhang ◽  
Ya Zhong Liu

As the grain size of nano ceramic has reached nanometer grade, it possesses high hardness, high wear resistance and high toughness. Therefore, the scalpel made by nano ceramic has the virtue of high wear resistance, good corrosion resistance, long service life, non-toxic, non-static, sharp edge and so on, but the processing of this kind of scalpel is extremely difficult. This paper prepares the nano-ceramic scalpel by using ELID grinding technology, and also studies the thickness, surface roughness, edge sharpness of scalpel. The research results show that the thickness of prepared scalpel is 0.3 mm, the surface roughness is 6-60 nm and the edge radius is 200 nm, the cutting experiment on suture shows that this scalpel can meet the requirements of international standard for medical scalpel when the cutting force is less than 0.8 N. This further proves that the ELID grinding technology is suitable for the preparation of nano-ceramic scalpel. The preparation technology and technological equipment of nano-ceramic scalpel are proposed on the basis of above achievements, and this technology possesses promising application prospect.


2009 ◽  
Vol 76-78 ◽  
pp. 38-42 ◽  
Author(s):  
Xavier Kennedy ◽  
S. Gowri

Advanced structural ceramics have been increasingly used in automotive, aerospace, military, medical and other applications due to their high temperature strength, low density, thermal and chemical stability. However, the Grinding of advanced ceramics such as alumina is difficult due to its low fracture toughness and sensitivity to cracking, high hardness and brittleness. In this paper, surface integrity and material removal mechanisms of Alumina ceramics ground with SiC abrasive belts, have been investigated. The surface damage have been studied with scanning electron microscope (SEM). The significance of grinding parameters on the responses was evaluated using Signal to Noise ratios.This research links the surface roughness and surface damages to grinding parameters. The optimum levels for maximum material removal and surface roughness been discussed.


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