Sergej Hloch

Sergej Hloch

About

257
Publications
87,710
Reads
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3,354
Citations
Additional affiliations
December 2016 - December 2016
March 2016 - March 2016
University of Osijek
Position
  • Lecturer
Description
  • Scientific Methodology
September 2013 - present
Institute of Geonics of the CAS, v.v.i. Ostrava-Poruba
Position
  • Researcher
Description
  • Research on Water Jetting

Publications

Publications (257)
Article
Full-text available
Maraging steel is one of the exotic materials showing the potential for application in the field of the aerospace industry. However, machining these materials with high surface quality and material removal rate is problematic. The micro-electro chemical discharge (MECDM) process is capable of resolving this problem to some extent, however, due to t...
Article
Full-text available
The local residual stresses (tensile) generated on the surface of a component during its manufacturing (machining, welding) cause deterioration of its service life. To eliminate the negative effect of the stresses, the surface is treated using different methods (shot peening, laser shock peening, heat treatment, water jet peening). The application...
Article
Full-text available
Non-thermally affected surfaces created by abrasive water jet, among many other advantages, are manufactured with geometric inaccuracies. These geometric inaccuracies are mainly related to waviness, especially in the lower parts of thick engineering components. Therefore, the study establishes a link between the surface quality and abrasive water j...
Article
Full-text available
This article deals with the analysis of the subsurface deformation effects of materials due to the periodic action of liquid droplets, each with a constant volume of approximately 36 mm³ distributed with a spatial frequency of 20,000 i/mm. Sample grooves were analyzed within standoff distances where the prevailing mechanism is acceleration culminat...
Article
This study focuses on the analysis of the surface material integrity of the polished, rigid, solid surface of an aluminium alloy after periodical impingement of liquid droplets with variable volume and impact frequency distributions normal to the solid surface. The volume of water droplets was determined for the pressures of 20 and 40 MPa. By incre...
Article
Full-text available
Peening techniques are nowadays attracting more research attention due to their association with the extending of the service life and improving surface texture of engineering components. Ultrasonic pulsating water jet peening represents a new way of mechanical surface treatment. Accelerated water droplets via hammer effect cause small elastic-plas...
Article
Full-text available
This study investigated the effect of abrasive water jet kinematic parameters, such as jet traverse speed and water pressure, on the surface of magnesium-based metal matrix nanocompo-sites (Mg-MMNCs) reinforced with 50 nm (average particle size) Al2O3 particles at concentrations of 0.66 and 1.11 wt.%. The extent of grooving caused by abrasive parti...
Article
Full-text available
This article deals with the effect of periodically acting liquid droplets on the polished surfaces of AISI 316L stainless steel and Ti6Al4V titanium alloy. These materials were exposed to a pulsating water jet produced using an ultrasonic sonotrode with an oscillation frequency of 21 kHz placed in a pressure chamber. The only variable in the experi...
Chapter
The use of pulsating water jet as a minimal invasive method for disintegration of bone cement requires optimal determination of its machine settings which effects the erosion depth. The volume of fluid required and the distance of the nozzle from the bone cement surface during its disintegration are one of the important machine settings for its in-...
Chapter
Pulsating water jet is a hybrid process of ultrasonic machining and waterjet machining. The continuous jet of the water is induced with ultrasonic disturbances resulting in forced breakup of the jet. The morphology of the jet is stimulated by ultrasonic transducer depend upon the frequency and power transmission. The transmission of the fluctuation...
Chapter
Tuning of an ultrasonic system for pulsating water jet technology for efficient power transmission is discussed in this paper. The efficiency of the ultrasonic transducer depends upon the stiffness of the water interacting with it. The stiffness of water depends upon the inlet volume flow rate inside the acoustic chamber controlled by supply pump p...
Chapter
Effect of the pulsating water jet on the plastic deformations of surface of Ti6Al4V was examined. Existing research papers investigating the interaction of Ti6Al4V with pulsating water and water impact are focused on culmination erosion stage of the impacted area. In this article, the initial stages of erosion were studied in term of the increasing...
Article
The present study focuses on the hydrodynamic erosion of tantalum in the form of the disintegration depth when exposed to periodic impingements of water clusters. Discrete water clusters were generated using a pulsating water jet at excitation frequencies of 20 and 40 kHz to modulate the continuous jet into a pulsating jet. The influence of the tec...
Article
Full-text available
This study compared the effect of the interaction time of periodic water clusters on the surface integrity of AISI 304 tungsten inert gas (TIG) welded joints at different excitation frequencies, as the effect of the technological parameters of pulsating water jet (PWJ) on the mechanical properties of TIG welded joints are under-researched. The TIG...
Book
This book reports on recent advances in the rapidly growing field of high-speed water jet technology, discussing research, developments and applications related to cutting, machining, repair of structures and buildings, cleaning, removal of coatings and layers, mining, and abrasive materials. It also explores special applications of high-pressure t...
Article
Full-text available
Liquid biofuels for compression ignition engines are often based on vegetable oils. In order to be used in compression ignition engine the vegetable oils have to be processed because of their high viscosity or it is also possible to use vegetable oils in fuel blends. In order to decrease the viscosity of the fuel blends containing crude vegetable o...
Book
Full-text available
This book reports on cutting-edge research and technologies in the field of advanced manufacturing and materials, with a special emphasis on unconventional machining process, rapid prototyping and biomaterials. It gathers contributions to the International Conference on Manufacturing Engineering and Materials (ICMEM 2020), which was originally plan...
Article
Full-text available
The water hammer effect is the basis of technologies which is artificially responsible for the decay of continuous jets. A recently developed technique enhances the pressure fluctuations using an acoustic chamber, leading to enhanced erosion effects for various water volume flow rates. The optimum standoff distance for an ultrasonic enhanced water...
Article
In this study, a new methodology is considered for determining the rotational senses (clockwise or anti-clockwise) of a workpiece during the hydroabrasive disintegration of rotating samples. The rotational directions are taken with respect to the position of the abrasive jet, that is, keeping it on the right side of the rotating workpiece when view...
Conference Paper
From centuries old technology, high pressure, lower volume water jet has been used for the erosion. Recently, due to economical limitation, the high-pressure pumps are replaced by the lower pressure pump by using the pulsed water jet technology. The mechanism includes the hitting of a flowing fluid with a solid body generating interim high pressure...
Conference Paper
Stainless steel 304 is one of the versatile material, is widely used in the medical industries due to the combination of biocompatible with good mechanical properties. It's better corrosion resistance properties which is suitable for the wide variety of biological applications. Typical uses are in the field of architectural, pharmaceutical and chem...
Article
Full-text available
Ultrasonic pulsating water jet for non-thermal and selective removal of acrylic bone cement is studied. Variation of acoustic chamber length is used for tuning of the ultrasonic system into the resonance regime to gain maximum power transmission. The study investigates the minimal technological conditions such as nozzle traverse speed and supply wa...
Chapter
The paper describes the interaction between pulsating water jet and surface of three different metals: 316L stainless steel, 6068 Al alloy and Ti6Al4V Ti alloy. The pulsating water jet is formed by using the ultrasonic sonotrode to the pressurized acoustic water chamber. It appears that the shape of the resulting water jet differs at various distan...
Chapter
The disintegration of the material by PWJ technology depends upon many technological parameters of the equipment and particular material properties. This paper deals with the erosive effects of PWJ on the polished surfaces of metallic materials such as titanium (Ti6Al4V) and aluminium (ENAW1050AH24) alloy. The evaluation and comparison of the exten...
Chapter
A brief definition of progressive technologies is difficult to implement due to the widely different processes that fall into this category. There is a consensus in the literature that this group includes processes that use conventional forms of energy in a new way. One of such technologies includes strengthening of surface layers with a pulsating...
Article
The study compares the sandstone erosion manifestations (depth, width, and volume of the removed material) caused by continuous and pulsed water jets (WJs) with a frequency f=20 kHz and 40 kHz. The WJ head follows an inclined trajectory at an angle of 45° to the horizontal surface. The starting point of the head was positioned 5 mm above the sandst...
Article
The objective of the study is to investigate the erosion effects of periodic water clusters interacting with flat AISI 304 surface to evaluate erosion regimes, surface morphology and variation in the subsurface microhardness below the disintegrated grooves. Stairs trajectory within the standoff distance 5–101 mm with step height 2 mm and length 20...
Article
This research article aims at comparing the erosion performance of continuous and ultrasonically generated pulsating water jet technologies on granite samples at three pressure levels of 20 MPa, 40 MPa and 60 MPa. The granite surface was eroded using the circular nozzle of diameter d ¼ 1.9 mm with the variation of traverse speed at each pressure le...
Article
Tool durability is an important parameter in the evaluation of the performance of the cutting tools and inserts. It is directly connected with tool wear that significantly affects the quality of the workpiece. Only from an understanding of the nature behind the machining process in given conditions (a combination of cutting parameters, machined mat...
Cover Page
Full-text available
Šesté mezinárodní setkání výrobců, uživatelů, tvůrců a zájemců o technologii vysokorychlostního vodního paprsku. Fórum k výměně názorů, informací a zkušeností v oblastech výzkumu, vývoje a aplikací vysokorychlostních vodních paprsků (řezání, obrábění, sanace konstrukcí a staveb, čištění, odstraňování povlaků a nánosů, hydrodemolice, těžba, abrazivn...
Article
The vehicle‘s tire rolling resistance in road traffic plays a significant role mainly in the fields of fuel consumption and produced harmful emissions. It also plays a significant role in measuring on the roller test stands. An inspection measurement has a task of revealing such vehicles in traffic which have a negative influence on the environment...
Article
Full-text available
Pulsating water jet technology for rock erosion application has been emphasized in this study. The erosion phenomena are explored as an eroded depth, eroded width and volume eroded of the sandstone at frequency f = 20,000–40,000 Hz by using pulsed water jet. The surface was eroded at pressure 20–40 MPa; standoff distance 20 mm; nozzle diameter 1.6...
Article
Friction stir welding has been successfully employed to fabricate dissimilar thickness AA1050 and oxygen free copper (Cu-OF). The highest value of the joint tensile strength obtained was 91% of the AA1050 alloy strength with the tensile fracture path on the aluminum side. At the Al-Cu interfacial microstructure, a layer of Al4Cu9 and Al2Cu intermet...
Article
This paper deals with performance analysis of disintegration of polymethylmethacrylate using pulsating liquids jet with different density with frequency 20 kHz using condition monitoring. The influence of the liquid on the cutting depth was studied by using contactless measurement device MicroProf, FRT. The cutting depths were compared to studies t...
Article
Full-text available
This paper deals with a research focused on utilization of microparticle and short-fiber filler based on cotton post-harvest line residues in an area of polymeric composites. Two different fractions of the biological filler (FCR—reinforced cotton filler) of 20 and 100 µm and the filler with short fibers of a length of 700 µm were used in the resear...
Article
Full-text available
This study addresses the erosion transition of an aluminium surface arising from the periodic impact of a tangentially acting pulsating water jet (PWJ) with a spatial frequency of f = 20 kHz. The erosion effect was observed as a function of the standoff distance z (mm) along an incline (from 5 mm to 90 mm) and constant trajectory (at standoff dista...
Article
The study compares the sandstone erosion manifestations (depth, width, and volume of the removed material) caused by continuous and pulsed water jets (WJs) with a frequency f = 20 kHz and 40 kHz. The WJ head follows an inclined trajectory at an angle of 45° to the horizontal surface. The starting point of the head was positioned 5 mm above the sand...
Article
Enhancement of the life of the engineering components is essential from the perspective of its performance, therefore, it is necessary to eliminate the negative effects that attenuates the life of these components. Numerous surface treatment methods are used at present out of which water jet peening process have been stated to overcome the shortcom...
Chapter
Abrasive water jet machining (AWJM) is successfully used for various industrial applications to cut extreme ductile and brittle materials. Thermal deterioration, high processing diversity, provide distinct advantages with high flexibility and small cutting forces. In this study, the Taguchi design analysis was used to determine the optimal combinat...
Chapter
In the drilling of flexible work pieces, the work piece movement makes the prediction of the machining time more difficult. This is due to the variance between the defined machining parameters and the effective machining conditions at the cutting edges. Consequently, feed rate strategies cannot be applied on the basis of the machining parameters. T...
Chapter
The paper deals with the change of the surface properties of the substrate after the application of multiple plasma spraying NiCr. The influence of selected technological factors (substrate material, surface angle of the substrate and degreasing of the surface) on topography and surface quality of the substrates. Presented procedures and experiment...
Article
The paper deals with the potential of employing accompanying physical phenomena, acoustic emissions, during monitoring of abrasive water jet disintegration of rotating workpiece. It focuses on the acquisition of theoretical knowledge about this technology with the aid of SEM surface analysis. Variation in traverse speed of the cutting head is used...
Chapter
Full-text available
Over the decades, water jet cutting has been widely used for rock disintegration in mining operations and quarrying purposes. The impact of high-pressure water jet on hard material like rock, coal ruins the original structure of the material; therefore, low-pressure water jet comes into the existence. In recent year, pulsating water jet has been ap...
Chapter
Full-text available
Abrasive water jet turning is one of the recently developed manufacturing technologies. It has gained its importance due to its capability to machine difficult-to-cut material with advantages such as absence of thermal effects, high machining flexibility and little cutting force. In this study, the influence of water jet turning parameters such as...
Chapter
Full-text available
The pressure of the waterjet influences the overall performance of the abrasive waterjet cutting system through operational and phenomenological effects. In this study, the effect of water pressure in surface quality of Mg-based nanocomposite was investigated. The as-machined surfaces were examined by field emission scanning electron microscope to...
Chapter
Full-text available
Water jet peening has gained attention as a potential surface treatment process for improving the fatigue life of a component. The tensile residual stress in the component initiates the stress corrosion cracking and reduces its fatigue life. The mitigation of this tensile residual stress can be effectively achieved by water jet peening process due...
Book
Full-text available
This book reports on cutting-edge research and technologies in the field of advanced manufacturing and materials, with a special emphasis on unconventional machining process, rapid prototyping and biomaterials. Based on the International Conference on Manufacturing Engineering and Materials (ICMEM 2018), held in Nový Smokovec, Slovakia on 18–22 Jun...
Article
Full-text available
The article deals with the measurement of micro-hardness of the track by the action of ultrasonic excitation of pulsating water jet. The cumulative effect of liquid matter in the form of droplets concentrated in waveform measurements was provided in horizontal and vertical direction to material core (AISI 304). The material was subjected to pressur...
Article
The paper deals with microhardness measurement up to a depth of 3 μm on hybrid metal matrix composite A359/Al2O3/B4C from the surface created by wire electric discharge turning and abrasive waterjet turning at the same of a range of rotational speed. The study also includes the topographical and morphological aspects of measurements to compare the...
Article
In this work, wire electric discharge turning, a novel and unconventional technique, was used for the turning operation of a newly developed hybrid metal matrix composite of aluminum (A359/B 4 C/Al 2 O 3 ) fabricated in-house by electromagnetic stir casting. The objective of the work was to examine the effect of rotational speed on the elements of...
Article
Full-text available
The present study is focused on the disintegration effect of ultrasound-enhanced pulsating water jet (PWJ) technology on brass CW614N. The first part of the study discusses the effect of a combination of factors based on the full factorial design of experiments (DoE) 3³. Traverse speed v (mm s⁻¹), circular nozzle orifice diameter d (mm), and hydrau...
Article
The residual stress and subsurface hardness of welded joints treated by peening using an ultrasonic pulsed water jet at pressures of 20–60 MPa with various traverse speeds and standoff distances were measured. The effect of the treatment was quantified by measuring the residual stress using X-ray diffraction in three regions (the welded zone, heat-...
Article
Full-text available
The ecological, economical and industrial benefits of pulsating water-jet it faces a new challenge in research era. Pulsating water-jet is an evaluation of water-jet technology. In pulsating water-jet technology researchers have done substantial work in a various field such mining, civil, mechanical, ornamentals, geology field. The main purpose of...
Article
Full-text available
Cemented carbide (CC) is an important material for the mining tools. During mining applications, the service life of the CC gets highly reduced due to complex conditions offered by mines. In various applications, such as, rock drilling and coal cutting, the tools show different type of wear behaviour. Wear assessment has been an important area of r...
Article
Full-text available
This paper addresses the hydroabrasive disintegration of the difficult-to-machine material, Monel K-500. An experiment was performed using a hydroabrasive cutting system with an additional rotating module. The objective of the preliminary experiments was to identify significant technological factors and investigate their impact on the machined surf...
Article
In this study, the effects of pulsating water jets were investigated as a surface treatment process using circular and flat nozzles by considering the integrity of a stainless steel (AISI 304) surface. The local energy distribution was controlled by changing the traverse speed and the pulsating water jet (PWJ) effects were assessed in terms of the...
Article
Full-text available
Pneumatic artificial muscles are pneumatic actuators with elastic structure distinctive for their nonlinear characteristics and hysteresis. In the paper we concentrate on the investigation of hysteresis in one of the recent types of fluidic muscles (DMSP-5). The main objective is to examine the hysteresis with respect to its rate-independence as we...
Article
The paper deals with interlaminar fracture toughness testing of three different types of specimens from unidirectional aerospace laminate M21/T800S (autoclaved and hot pressed) and the woven fabric ECG Carbon 12k with respect to the ASTM Standard D5582. Simultaneously the materials were monitored by acoustic emission to evaluate the results via bur...
Article
Full-text available
The paper deals with the tangential abrasive water jet turning of hybrid aluminium matrix composite fabricated by electromagnetic stir casting technology, consisting A359 aluminium alloy as base matrix and 2% B4C and 2% Al2O3 as reinforcing particles with final workpiece diameter of 14.5 mm. The influence of abrasive mass flow rate within 100–400 g...