- TITLE:
COATING OF ST37 STRUCTURAL STEEL SURFACE WITH WC-ST6-ST21 AND FERRO55 USING LASER CLADDING TECHNIQUE AND INVESTIGATION OF SURFACE HARDNESS
- AUTHOR(S):
B. Avci, I. Dalmis, S. Yilmaz
- ABSTRACT:
Improving material properties such as surface hardness and wear resistance play a vital role in modern industrial applications. Surface coating techniques offer a practical approach to achieve these improvements. This study focuses on laser cladding as a method to coat ST37 structural steel material with WC, ST6, ST21 and Ferro55 powders and investigates the resulting surface hardness. ST37 structural steel with a base hardness of 120 HV was used as the starting material. Laser cladding was used to apply WC, ST6, ST21 and Ferro55 powders to the steel surfaces using various process parameters. Hardness measurements of the laser cladded samples were carried out using HV0.3 load for evaluation. The study examines the surface hardness differences between ST37 steel samples coated with different powders, highlighting the highest and lowest hardness values.
- DOI:
https://doi.org/10.62853/YGOC5192
- PAGES:
86-89
- DOWNLOAD:
COATING OF ST37 STRUCTURAL STEEL SURFACE WITH WC-ST6-ST21 AND FERRO55 USING LASER CLADDING TECHNIQUE AND INVESTIGATION OF SURFACE HARDNESS
- HOW TO CITE THIS ARTICLE:
Avci B., I. Dalmis, S. Yilmaz. Coating of St37 structural steel surface with WC-ST6-ST21 and ferro55 using laser cladding technique and investigation of surface hardness. Journal of the Technical University of Gabrovo. 67 (2023) 86-89.
- TITLE:
ANALYSIS OF ADDITIVELY MANUFACTURED AlSi10Mg ALLOY USING X-RAY DIFFRACTION
- AUTHOR(S):
J Čapek, K. Trojan, R. Halama, N. Ganev, J. Hajnyš, K. Kolařík
- ABSTRACT:
This research deals with the study of additively manufactured AlSi10Mg alloy samples by X-ray diffraction. The effect of sample orientation during 3D printing by Selective Laser Melting on the values of macroscopic residual stresses and microstructural parameters and their possible inhomogeneities of the cylindrical sample was investigated. Phase analysis identified the intermetallic phase Mg2Si in addition to the major phases (solid solutions of Al and Si). Tensile residual stresses weredetected in the surface layer for all samples. Inhomogeneities of the investigated parameters of all samples were observed along the circumference of the shank. These effects may be related to the direction of the layers relative to the axis of the sample. These inhomogeneities form so-called microstructural notches or weak spots that are prone to the formation of fatigue cracks, which have a major influence on the fatigue life.
- DOI:
https://doi.org/10.62853/MHIN4664
- PAGES:
84-85
- DOWNLOAD:
ANALYSIS OF ADDITIVELY MANUFACTURED AlSi10Mg ALLOY USING X-RAY DIFFRACTION
- HOW TO CITE THIS ARTICLE:
Capek J., K. Trojan, R. Halama, N. Ganev, J. Hajnys, K. Kolarik. Analysis of additively manufactured AlSi10Mg alloy using X-ray diffraction. Journal of the Technical University of Gabrovo. 67 (2023) 84-85.
- TITLE:
PRODUCTION AND CHARACTERIZATION OF 2024 ALUMINUM ALLOYS
- AUTHOR(S):
C. Misirli
- ABSTRACT:
This study aims to give theoretical information about the production and characterization of mechanical properties of 2024 aluminum alloys. AA2024 alloy; It consists of components such as aluminum, copper, magnesium and manganese, and the production of the alloy is usually carried out by different methods such as casting, rolling, extrusion and powder metallurgy. The choice between production methods should be made by considering the purpose and properties of the alloy. While the casting method is used for the production of large-sized parts, the rolling method is suitable for the production of thin sheets and strips, and the extrusion method is suitable for the production of profiles and pipes of various shapes. The powder metallurgy method, on the other hand, is carried out by shaping the powdered components of the alloy with a special pressing process and then sintering at high temperature. Alloys produced by this method exhibit high strength properties with their high density and homogeneous microstructures. The mechanical properties of AA2024 alloy are generally determined using various characterization methods such as tensile test, hardness measurement and fatigue life tests. The tensile test is used to determine the tensile strength, tensile elongation ratio and elastic tension properties of the alloy. The hardness measurement is used to determine the surface hardness of the alloy. Surface hardness can be performed using Brinell, Vickers and Rockwell hardness measurement methods. The fatigue life test is used to determine the fatigue strength of the alloy. In this test, the fatigue life of the specimen under repetitive loads is determined. The mechanical properties of AA2024 alloy may vary depending on production methods, alloy components, temperature and environmental conditions. Therefore, the mechanical properties of the alloy must be optimized for a particular application. 2024 aluminum alloys produced by powder metallurgy method are expected to exhibit high density, homogeneous microstructure and high strength properties as a result of hardness, tensile and fatigue tests.
- DOI:
https://doi.org/10.62853/DHIC1076
- PAGES:
80-83
- DOWNLOAD:
PRODUCTION AND CHARACTERIZATION OF 2024 ALUMINUM ALLOYS
- HOW TO CITE THIS ARTICLE:
Misirli C. Production and characterization of 2024 aluminum alloys. Journal of the Technical University of Gabrovo. 67 (2023) 80-83.
- TITLE:
INVESTIGATION OF MICROSTRUCTURE OF AA7075 ALLOYS AFTER SEVERE PLASTIC DEFORMATION APPLICATION
- AUTHOR(S):
C. Misirli
- ABSTRACT:
The aim of this study is to investigate the change of microstructural properties of AA7075 alloys after severe plastic deformation. Severe Plastic Deformation is a process used to improve the properties of the material by creating intense plastic deformations on the material surface. Equal channel angular compression molding (ECAP) was used for the severe plastic deformation process in our study. AA7075 alloy samples were primarily prepared for severe plastic deformation treatment. Then, the microstructural properties of the samples were investigated using various imaging techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The research results showed that significant microstructural changes occurred in AA7075 alloys after the severe plastic deformation process. The SPD process improved the mechanical properties of the material by transforming the crystalline structures of the material into a fine-grained structure. In addition, it was observed that deformation lines and pits occurred on the surface of the samples after the SPD process. It is seen that the SPD treatment increases the mechanical properties of the material such as strength, hardness and durability. Therefore, this study is an important step towards the development of the alloy's use in various industries.
- DOI:
https://doi.org/10.62853/IKYZ3491
- PAGES:
77-79
- DOWNLOAD:
INVESTIGATION OF MICROSTRUCTURE OF AA7075 ALLOYS AFTER SEVERE PLASTIC DEFORMATION APPLICATION
- HOW TO CITE THIS ARTICLE:
Misirli C. Investigation of microstructure of AA7075 alloys after severe plastic deformation application. Journal of the Technical University if Gabrovo. 67 (2023) 77-79.
- TITLE:
PERFORMANCE ANALYSIS OF CONTINUOUS LINEAR MOTION OF SINGLE AND SERIES CONNECTED PIEZOELECTRIC ELEMENTS BY USING METHOD OF IMPACT DRIVE MECHANISM
- AUTHOR(S):
Kuscu H., Kaya U.
- ABSTRACT:
IDM can be defined as the transformation of small vibrations of a piezo element into continuous linear motion on a frictional surface by controlling the extension and contraction speed thus the impact force. In most of previous studies, longitudinal vibrations of piezo elements are employed as in [1], [2], [3] to obtain a continuous linear motion. In this study, linear continuous motion characteristics of series connected piezoelectric (PZT) crystals are investigated both numerically and experimentally, when the method of the impact drive mechanism applied was driven by coupled transverse and torsional vibrations. For the experiments, PZT rectangular crystal bars are series connected with a neodymium magnet glued to the bottom end, and then positioned to a grinded smooth steel surface. The three test specimens were series connected one, two, and three-elements PZT-5X military grade single crystals, and the neodymium magnets were N38 grade coated with nickel. Before starting the tests, resonant frequencies of test specimens are calculated numerically by making harmonic analysis employing a finite element software (ANSYS) and tested experimentally by using the sweep characteristics of the signal generator. Triangular, and sine signal waves at resonance frequencies are applied for each test specimen at 220 Volts. Both the numerical and experimental results showed that the top-end deflection, strain energy, the impact force thus the linear velocity increases by increasing the number of PZT crystal elements of a test specimen. The research conducted here could be supportive when designing nano/micro-scale positioning actuators and driving systems for different kinds of high technology applications.
- DOI:
https://doi.org/10.62853/NJJN9041
- PAGES:
70-76
- DOWNLOAD:
PERFORMANCE ANALYSIS OF CONTINUOUS LINEAR MOTION OF SINGLE AND SERIES CONNECTED PIEZOELECTRIC ELEMENTS BY USING METHOD OF IMPACT DRIVE MECHANISM
- HOW TO CITE THIS ARTICLE:
Kuscu H., Kaya U. Perfomance analysis of continuous linear motion of single and series connected piezoelectric elements by using method of impact drive mechanism. Journal of the Technical University of Gabrovo. 67 (2023) 70-76.
