Cavitation Erosion Tests Performed by Indirect Vibratory Method on Stainless Steel Welded Samples with Hardened Surface

The paper presents the results of cavitation erosion tests performed on two types of samples. The materials of the samples are frequently used for manufacturing and repairs of the hydro turbines components submitted to cavitation. The first sample was made by welding of an austenitic stainless steel on austenito-feritic base material. The second sample was made similarly with the first but with a martensitic base material. After the welding processes, on both samples was applied a hardening treatment by surface peening. The cavitation erosion tests were performed on vibratory equipment using the indirect method with stationary specimen. The results show a good cavitation erosion resistance on both samples

Dry Sliding Wear behavior of some Cu and Al Alloys

In this paper, a study concerning the dry sliding wear behavior of three Cu and Al alloys namely CuSn12, CuAl10Fe3 and AlSi12 was made. For this three alloys type, all tests have been performed with a tribometer using the pin-on-disk method (POD) according to the ASTM G99 standard, where the working conditions (applied load, linear speed, motor speed and distance) were the same. As an important parameter, the coefficient of friction (COF) versus time / distance was monitored respective the wear rate coefficient was calculated. The obtained results were compared between them, and the specific images were acquired through a digital microscope and specialized software. In addition, to these tests, the hardness of these alloys was carried out using a Vickers microhardness tester

Equation of Motion and Determining the Vibration Mode Shapes of a Rectangular Thin Plate Simply Supported on Contour Using MATLAB

This paper presents the differential biharmonic equation of thin plates through which, the vibration mode shapes for a rectangular thin plate simply supported on contour were obtained. Also, the first four vibration mode and the first four natural frequencies of this rectangular thin plate of steel, were obtained. Using MATLAB software, the vibration mode shapes were graphically represented

Calibration Tests of a Sonotrode and Cavitation Erosion Research through Indirect Cavitation Method for a Steel

This paper content the describe of cavitation erosion stand, especially the ultrasonic generator; the calibration tests of a oxidable steel sonotrode and the experimental results for a specimen also from oxidable steel material tested at cavitation erosion through the indirect cavitation method

Wear Resistance Assessment of Fluoropolymer Coated Gears

Power transmissions that incorporate gears dissipate a significant amount of energy and noise. Thus, any improvement in their performance contributes to reducing energy consumption and noise pollution. In recent years, the opportunities offered by conventional technologies to increase gear performance have been fully exploited. Therefore, surface depositions on gear teeth have become increasingly important technologies in achieving objectives such as: improving energy performance, providing greater protection against superficial defects, increasing load capacity and reducing acoustic emissions generated during operation. However, gear coating technologies have begun to be developed, but the investigations are still insufficient. In this study, we carried out wear resistance investigations performed on fluoropolymer coatings for different working speeds, loads and lubrication conditions. The results point out that the deterioration rate of the coating increases with the increase of the working speed and the applied load. In addition, a slight lubrication, applied at the start of testing, leads to a noticeable improvement in wear behaviour. This study represents one step further in understanding the wear process of fluoropolymer coated gear

Cavitation Erosion Research for AlSi12 Alloy Tested at Different Time Periods

This paper presents cavitation erosion research for 2 batch of an AlSi12 alloy. The tests were made on a cavitation stand in laboratory, using the stationary specimen method. This alloy is not subject to cavitation, but the experimental research highlight the behavior of AlSi12 alloy when the time periods are different. The research results are presented through graphs and representative images

Cavitation Erosion Research for AlSi12 Alloy Tested at Different Time Periods

This paper presents cavitation erosion research for 2 batch of an AlSi12 alloy. The tests were made on a cavitation stand in laboratory, using the stationary specimen method. This alloy is not subject to cavitation, but the experimental research highlight the behavior of AlSi12 alloy when the time periods are different. The research results are presented through graphs and representative images

Study Regarding the Good Cavitation Erosion Resistance of a 13Cr-4Ni Stainless Steel used to Manufacture the Components Exposed to Water of the Hydraulic Turbines

This paper presents some information regarding the hydraulic turbines respectively the experimental results on cavitation erosion behavior of a 13Cr-4Ni stainless steel used to manufacture the components exposed to water of the Francis, Kaplan and Pelton hydraulic turbines. So, the presented experimental results of this paper highlight the good cavitation erosion resistance of the analyzed 13Cr-4Ni stainless steel

Comparative Study on the Cavitation Erosion Resistance Experimental Results of Some Steels Tested through the Cavitation Indirect Method

This paper presents the experimental results of cavitation erosion research regarding the resistance of some steels. So, the cavitation erosion researches involve tests of hours for each test. These results are in tabular form, through charts and pictures presented in this paper

Influence at Work Distance between the Sonotrode and Specimen to Cavitational Erosion

The paper presents the results of cavitation erosion tests performed on five samples from pure aluminum using the vibratory method with stationary specimen. The main purpose of this research is for determine which is the distance between the sonotrode and specimen favorable for an aggressive cavitational attack. For this, has been calculated the Mean Depth of Erosion (MDE) and the cavitation erosion rate (Vec). After that the specific curve for Vec has been analytically processed