scholarly journals The results of water droplet erosion tests of ion-plasma coatings formed on titanium Ti-6Al-4V alloy samples manufactured by using 3D-printing and traditional technological process

Author(s):  
Alexey F Mednikov ◽  
Alexander B Tkhabisimov ◽  
Olga S Zilova ◽  
Andrey A Burmistrov ◽  
Sergey V Sidorov
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dingjun Li ◽  
Peng Jiang ◽  
Fan Sun ◽  
Xiaohu Yuan ◽  
Jianpu Zhang ◽  
...  

Abstract The water-droplet erosion of low-pressure steam turbine blades under wet steam environments can alter the vibration characteristics of the blade, and lead to its premature failure. Using high-velocity oxygen-fuel (HVOF) sprayed water-droplet erosion resistant coating is beneficial in preventing the erosion failure, while the erosion behavior of such coatings is still not revealed so far. Here, we examined the water-droplet erosion resistance of Cr3C2–25NiCr and WC–10Co–4Cr HVOF sprayed coatings using a pulsed water jet device with different impingement angles. Combined with microscopic characterization, indentation, and adhesion tests, we found that: (1) both of the coatings exhibited a similar three-stage erosion behavior, from the formation of discrete erosion surface cavities and continuous grooves to the broadening and deepening of the groove, (2) the erosion rate accelerates with the increasing impingement angle of the water jet; besides, the impingement angle had a nonlinear effect on the cumulative mass loss, and 30° sample exhibited the smallest mass loss per unit area (3) an improvement in the interfacial adhesion strength, fracture toughness, and hardness of the coating enhanced the water-droplet erosion resistance. These results provide guidance pertaining to the engineering application of water erosion protective coatings on steam turbine blades.


Author(s):  
Zheyuan Zhang ◽  
Tianyuan Liu ◽  
Di Zhang ◽  
Yonghui Xie

Abstract In this paper, a method for predicting remaining useful life (RUL) of turbine blade under water droplet erosion (WDE) based on image recognition and machine learning is presented. Using the experimental rig for testing the WDE characteristics of materials, the morphology pictures of specimen surface at different times in the process of WDE are collected. According to the data processing method of ASTM-G73 and the cumulative erosion-time curves, the WDE stages of materials is quantitatively divided and the WDE life coefficient (ζ) is defined. The life coefficient (ζ) could be used to calculate the RUL of turbine blades. One convolutional neural network model and three machine learning models are adopted to train and predict the image dataset. Then the training process and feature maps of the Resnet model are studied in detail. It is found that the highest prediction accuracy of the method proposed in this paper can be 0.949, which is considered acceptable to provide reference for turbine overhaul period and blade replacement time.


Author(s):  
Diana Hlushkova ◽  
Alexander Voronkov ◽  
Natalia Kalinina ◽  
Vasily Kalinin ◽  
Sergey Demchenko ◽  
...  

Author(s):  
K. V. Diadiun

Providing an increase in the working capacity of a metal-cutting tool, it is possible to significantly increase the productivity of mechanized labor, thereby reducing the cost of purchasing a new tool and saving on other accompanying technological components. During the operation of the cutting tool, the main load is transferred to its working part, this, as a rule, leads to partial wear or complete destruction of the planes and cutting edges. There are a number of technologies for processing working surfaces, which provides them with additional strengthening, the most effective of which is the method of applying special coatings to the surface of the cutting tool. Taking into account the specifics of the processes of formation of coatings, they can be divided into three main groups [1]. The first group includes methods in which the formation of coatings is carried out mainly due to diffusion reactions between saturating elements and structures of the instrumental material. The second group includes methods of forming coatings by a complex mechanism. The third group includes methods of forming coatings due to chemical and plasma-chemical reactions of particle flux simultaneously in volumes of space immediately adjacent to the saturable surfaces of the instrumental base. One such technology is the CIB (condensation and ion bombardment) method, which is a physical deposition of coatings. The most characteristic feature of coatings produced by this method is the absence of a transition zone between the coating and the tool material. This makes it possible to obtain a complex of properties on the working surfaces of the tool without deteriorating its original properties. The article is devoted to the issues of increasing the efficiency of ion-plasma technologies through the development and implementation of an automated system for analyzing and controlling the mass balance of reagent gases under conditions of several gases supply. Thus, the improvement of the technology of coating the working surfaces of the cutting tool, namely, the effective control of the process of applying ion-plasma coatings with the introduction of an automated system for analyzing and controlling the mass balance of reagent gases under conditions of supplying several gases is an urgent task.


2021 ◽  
Author(s):  
Rizwan Ahmed Shaik ◽  
Abdullahi K Gujba ◽  
Martin D. Pugh ◽  
Mamoun Medraj

Wear ◽  
2019 ◽  
Vol 426-427 ◽  
pp. 507-517 ◽  
Author(s):  
Charles B. Burson-Thomas ◽  
Richard Wellman ◽  
Terry J. Harvey ◽  
Robert J.K. Wood

2016 ◽  
Vol 25 (8) ◽  
pp. 1711-1723 ◽  
Author(s):  
F. Tarasi ◽  
M. S. Mahdipoor ◽  
A. Dolatabadi ◽  
M. Medraj ◽  
C. Moreau

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