Milan Honner

University of West Bohemia · New Technologies - Research Centre

Laser-induced water ablation triggers various physical effects, including atom ionization, optical breakdown of the liquid, phase explosion, cavitation, and shockwave propagation. These effects can be further amplified in heavy water by deuterium-deuterium fusion reactions, which require extremely high energy levels. Laser pulses can be grouped in...

An outbreak of infectious diseases has highlighted the importance of the early detection and prevention of high temperatures or fevers, which are some of the main symptoms of many diseases. Thermal cameras have become a promising tool for the detection of fever due to their non-invasive, non-contact and rapidly inspecting nature. By using person id...

Laser pulse duration is one of the important parameters that is able to dramatically change ablation efficiency. Shorter laser pulse duration leads to deeper transport of absorbed energy in subsurface material layers. Ultra-fast and non-equilibrium processes are able to remarkably affect residual energy, which is accumulated in the deeper subsurfac...

The invention is that the casing (4) of the cover has in the working part at least one outlet opening (6) for laser heating and non-contact measurement of the surface (3) of the measured material (23), which is placed in the working space (13) and furthermore, the casing (4) of the cover has in the service part at least one inlet opening (5) locate...

Laser surface texturing (LST) is one of the most promising technologies for controllable surface structuring and the acquisition of specific physical surface properties needed in functional surfaces. The quality and processing rate of the laser surface texturing strongly depend on the correct choice of a scanning strategy. In this paper, a comparat...

The device for thermographic temperature measurement consists of at least one calibration thermal element and a detector, which are fixed in a housing, while the calibration thermal element occupies part of the field of view.

The invention relates to the field of quantitative thermography, in particular thermographic measurement of the temperature of persons, but also to other applications where there are increased demands on the accuracy of non-contact determination of the area distribution of the measured temperature and focuses in particular on devices for accurate t...

Non-contact temperature measurement of persons during an epidemic is the most preferred measurement option because of the safety of personnel and minimal possibility of spreading infection. The use of infrared (IR) sensors to monitor building entrances for infected persons has seen a major boom between 2020 and 2022 due to the COVID-19 epidemic, bu...

Increased temperature in humans is the symptom of many infectious diseases and it is thus an important diagnostic tool. Infrared temperature measurement methods have been developed and applied over long periods due to their advantage of non-contact and fast measurements. This study deals with a statistical evaluation of the possibilities and limita...

Surface functionalization as well as the microstructure modification of electrodes by laser material processing has become increasingly important in recent years. Short and ultra-short pulsed lasers, which enable high-precision processing, are used for this purpose. However, the process mechanisms, such as the surface temperatures that emerge durin...

Formation of Laser Induced Periodic Surface Structures (LIPSS) is a very interesting phenomenon. As the process is now moving towards the industry for the production of functional surfaces, a monitoring technique for online process control is needed. In the present work, the process was investigated for the first time using fast infrared radiometry...

Increased temperature of humans is one of the symptoms of many infectious diseases and it is thus an important diagnostic tool. A contact based temperature measurement is a proven standard. However, infrared methods have also been developed and applied over a long period due to their advantages of a non-contact and fast measurement. This study deal...

The basis of the invention is that the heated area of the material is heated by a non-contact heating heat flow and after the heating is completed in the cooling phase at a predetermined time the surface temperature homogenization in the emissivity evaluation area measured areas, and in the individual places of the emissivity evaluation area, the e...

Laser surface hardening is one of the most advanced surface modification techniques to increase the wear resistance of large-sized and complexly shaped metal products. In this study, the laser transformation hardening process for the high-quality surface treatment of the steel products is applied using a high-power disc laser with extremely good be...

A unique combination of the ultrashort high-energy pulsed laser system with exceptional beam quality and a novel Diffractive Optical Element (DOE) enables simultaneous production of 2601 spots organized in the square-shaped 1 × 1 mm matrix in less than 0.01 ms. By adjusting the laser and processing parameters each spot can contain Laser Induced Per...

The paper deals with a new approach to laser thermography for the inspection of coating thickness. The approach is based on scanning the specimen surface point by point, using a low-power laser, and recording the temperature responses with an IR camera. A recorded sequence is then transformed into a sequence similar to a flash pulse thermography se...

ncreased temperature in humans is one of symptoms of infectious diseases. Infrared thermography is a popular method for measuring temperature as it offers fast and non-contact temperature measurement. However, and despite many advantages, its real accuracy for human temperature measurement is not sufficient in many cases. This study was focused on...

Device for thermographic temperature measurement, characterized in that at least one calibration thermal element (5) and the detector (1) are mounted in a housing (6), the calibration thermal element (5) being permanently located in the field of view (7). https://patents.google.com/patent/CZ35949U1/en

Ultrashort pulse laser micromachining is affected by the heat accumulation resulting from the residual heat from previous laser pulses on the sample surface. Up to now, most of the works analysed the accumulation by numerical modelling. The present work focussed on development and application for the first time of a measurement system of heat accum...

A shifted laser surface texturing method (sLST) was developed for the improvement of the production speed of functional surface textures to enable their industrial applicability. This paper compares the shifted method to classic methods using a practical texturing example, with a focus on delivering the highest processing speed. The accuracy of the...

Infrared camera comparative measurement methods of thermally optical properties of materials are based on the measurement of infrared radiation emitted from the surface of the material that is heated to a higher temperature. These methods compare the response of the analyzed material with the set of reference materials called standards. Standards a...

In this paper, a new measurement system and a new approach in calculation for infrared (IR) radiation investigation in quasi-simultaneous transmission laser welding of plastics are presented. The measurement system is based on a MW/SWIR (medium-wave/short-wave IR) camera and optical filters narrowing the spectral region to SWIR. The measured signal...

Coatings deposited on a material surface are effective way of changing its surface properties. For increasing or decreasing radiation heat transfer, coatings with high or low emissivity are used. Measurement of spectral emissivity is a fundamental step to effective use of coatings for this application. Up to now the measurement methods are focused...

The paper deals with uncertainty analyses of the new laboratory method for the measurement of spectral emissivity of high-temperature coatings. These coatings are intended to increase heat transfer in various industrial applications. The experimental set-up of the method is shortly introduced. The method is innovative in the application of scanning...

A three-dimensional model of direct heat treatment of a sample surface with a moving laser has been established utilizing the finite element method. Attention is devoted to the preparation of complex boundary conditions of a moving heat source. Boundary conditions of material heat treatment are defined in the form of the heat transfer coefficient w...

Utility model (PUV): Thermographic camera for quantitative temperature fields measurement (CZ:Termovizní kamera pro kvantitativní měření teplotních polí). Utility model (PUV) - national; app. no. PUV 2016-32519; reg. date 29.06.2016; Owner: Západočeská univerzita, Plzeň, CZ; Authors: Milan Honner, Michal Švantner (utility model - rejected)

The development of an experimental mathematical model describing temperature state of the sample during high temperature spectral emissivity measurement is introduced. Dimensional analysis of the measurement process gives the physical dimensionless quantities and sensitivity analysis of the measurement process provides the large set of performed mo...

The aim of the performed work is to establish the 2D and 3D model of direct unsteady task of sample heat treatment by moving source employing computer model on the basis of finite element method. Complex boundary condition on heat loaded sample surface is the essential feature of the task. Computer model describes heat treatment of the sample durin...

A new non-contact laser heating method for the normal spectral emissivity measurements of high-temperature coatings is introduced. The method utilizes laser source in combination with scanning optics. General and specific requirements for the method development are discussed. Works on the development of the optimal heating strategy to ensure homoge...

Computer model of temperature distribution in the sample in high temperature spectral emissivity measurement method is introduced. Sensitivity analysis is performed using computer model to determine the effect of various measurement method parameters on the sample temperatures. The effects of measured and reference coating thicknesses, measured coa...

Fatigue properties are among the very important material parameters, whose testing is expensive and time consuming. Thermographic inspection of the cyclically loaded samples could possibly be a method, how to reduce the expenses of fatigue tests. Principles of cyclic loading thermographic inspection and methods of evaluation are presented in this c...

A survey of the state of the art in the field of spectral directional emissivity measurements by using radiometric methods is presented. Individual quantity types such as spectral, band, or total emissivity are defined. Principles of emissivity measurement by various methods (direct and indirect, and calorimetric and radiometric) are discussed. The...

Optical properties of materials have significant effect on laser processes. Laser beam interacts with a material as light and absorptivity of the material to this light determines the amount of heat that is coupled to the material. The other light is lost. Emissivity determines cooling effects during and after the process by radiation heat transfer...

A new experimental device for normal spectral emissivity measurements of coatings in the infrared spectral range from 1.38 μm to 26 μm and in the temperature range from 550 K to 1250 K is presented. A Fourier transform infrared spectrometer (FTIR) is used for the detection of sample and blackbody spectral radiation. Sample heating is achieved by a...

Continuous furnaces are commonly used for steel billet reheating before a rolling operation. It is neces- sary to perform a number of measurements to set-up and operate the optimization system of the fur- naces correctly. A charge temperature measurement using infrared detectors can be one of the usable measurement techniques. This non-contact meas...

Device for making surfaces of high roughness and specific mechanical properties (CZ: Zařízení pro vytváření povrchů o vysoké drsnosti a specifických mechanických vlastnostech); Utility model - national; app. no. 2013-27458; reg. no. 25604; reg. date 15.02.2013; Owner: Západočeská univerzita, Plzeň, CZ; Authors: Michal Švantner, Milan Honner, Matěj...

Patent: A method and a device for producing surfaces of high roughness and specific mechanical properties (CZ: Způsob a zařízení pro vytváření povrchů o vysoké drsnosti a specifických mechanických vlastnostech); Patent - national; app. no. 2013-108, doc. no. 307120; reg. date 15.02.2013; Owner: Západočeská univerzita, Plzeň, CZ; Authors: Michal Šva...

The research work presented in this paper shows influence of filler composition in inorganic composite on its emissivity. Chromium Oxide is an active ingredient, which is present in the basic formula of BG HitCoat®. Also other active ingredients (Iron powder, Kaolin, Silicon Carbide, Boron Carbide, Boron Nitride and Aluminum Nitride) were built in...

The paper deals with heat flux measurement possibilities in fire safety applications. The paper presents two methods for radiation heat flux measurement – the thermography source-target measurement method, and the radiation contact target measurement method. Both the methods were used simultaneously for radiation heat flux measurement during a fire...

Detailed analysis of the entire reheating process obeying energy balance is presented. A complex mathematical model involving radiative heat transfer, conduction and simple combustion is systematically used to design an optimization control algorithm with respect to real technological and process constraints, which are handled in straight manner. A...

The contribution deals with the methodology of determination of the effect of coatings deposited on the inner surface of the electric furnace on the charge heating. The demonstrative results of measuring using the laboratory furnace with replaceable inner wall inserts are involved. These wall inserts are prepared from the two types of thermal insul...

High power laser - total emissivity method (HPL-TE method) for determination of coatings relative total emissivity dependent on the temperature is introduced. Method principle, experimental and evaluation parts of the method are described. Computer model of HPL-TE method is employed to perform the sensitivity analysis of the effect of method parame...

This paper deals with processes of thermoelastic instability occurring on brake systems that become evident as a non-uniform distribution of temperature with hot spots on contact surfaces. Thermoelastic instability is accompanied by the exponential rising of temperature amplitudes of hot spots during its initial linear phase. The authors discuss di...

This article deals with the application of the stochastic Exodus method for modelling of thermal spraying heat transfer processes and for solving direct and indirect problems. The Exodus stochastic method has an advantage in straightforward solving of the transient inverse heat transfer multi-dimensional problems over other methods based on iterati...

This paper deals with the introduction of a measuring system for application in research on the thermomechanical coupling of disc brakes. The first part is devoted to a description of the system for fast measurement of the brake disc surface temperature field during braking, which is the main part of the measuring system. The structure of the hardw...

The contribution deals with the introduction of the measuring system for the application in the research of thermo-mechanical instabilities of disc brakes. The first part is devoted to the description of the system for fast measurement of the brake disc surface temperature field during braking, which is the main part of the measuring system. The se...

This paper deals with the application of the stochastic Exodus method in simulation of the heat transfer processes in the multi-layer structure of thermal barrier coating. A 2D computer simulation model of thermal barrier behaviour during its dynamic thermal loading is presented. The Exodus stochastic simulation method has been applied to solve the...

Thermal box-barriers (TBB) are used for the thermal protection of measuring systems during exposure in a high temperature environment of various furnaces. This paper deals with problems of TBB design. TBB characteristics and limitations are discussed. The four-layer TBB structure is proposed for the high temperature application. The computer simula...

The hole drilling residual stress measuring method is based on drilling a small hole in a material sample and measuring the strain relieved in the hole vicinity by a special strain gauge rosette. The temperature and thermal strain induced by the drilling process can cause significant errors in the relieved strain measurement. The paper deals with c...

A computer simulation model of billet heating process in continuous pusher-type furnace is presented. The Exodus stochastic simulation method is used to solve the heat conduction partial differential equation. This paper deals with the application of the Exodus method in the furnace optimal heating-control system. A comparison of the computed resul...

The paper deals with methods and results of thermography analyses of the hole-drilling residual stress measuring technique. Surface IR properties of the drilling mill and sample with strain gauge rosette of millimeter dimensions are determined by the emissivity and reflectivity measurements. Dynamic surface temperature field measurement is accompan...

This paper deals with thermography applications in technology research, including the measurement of the heat treatment of large crankshafts, test and measurement of thermal barrier coatings, analysis of the hole- drilling residual stress measuring technique, the thermal spraying of protective coatings, measurement and evaluation of hot-air solderi...

The paper deals with the measurement in continuous industrial furnaces. Measuring technique and measuring device are presented. Temperature evolutions are measured on the experimental billet and records of the furnace heating-control system are shown. Furnace distributions of temperature, heat flux, and heat transfer coefficient are determined by m...

Résumé: This book is theoretically and experimentally focused on thermal barriers. It consists of three independent parts dealing with thermal barrier coatings (TBC), thermal box-barriers (TBB) and natural thermal barriers (TBN). The thermal barrier coatings serve mainly to material protection against high temperatures. Thermal box-barriers introdu...

Thermal barriers (TB) protect material against high temperatures and thermal shocks. The effect of various TB - substrate structures to their dynamic behaviour under the thermal shock is studied. The TB parameters such as number of individual layers, their thicknesses and porosities and thermal and mechanical properties of their materials have been...

The contribution presents the development on the optimal heating control system for con-tinuous furnaces. Concept and basic description of the optimization system are introduced. Partial focus is devoted to the CFD computations of thermo-mechanical processes in the in-ternal furnace space and to the ways of measurement in continuous furnaces.

The aim of the contribution is to present the current computational capabilities and results of thermomechanical processes simulation in the industrial furnace. Three-dimensional model of the continuous pusher-type furnace employed in mild rolling mill has been created. The resultant velocity and temperature distributions inside the furnace, heat f...

Microscale nonequilibrium heat conduction appears in all states of matter including solids, liquids, gases and plasmas where heat is carried by phonons, atoms, molecules, electrons or photons. A unified model of diffusion, wave and parallel conduction is introduced. Internal parameters and conditions of unambiguity describing the nonequilibrium are...

This paper deals with one-dimensional simulation of heat waves, which occur in materials affected by pulsed or continuous surface heat source. The mathematical model is constructed according to the extended hyperbolic heat conduction (EHHC) theory. Effects of relaxation numbers, surface emissivity, or surface heat convection transfer are discussed....

A unified description of two physically different wave diffusion and parallel nonequilibrium heat conductions is presented. Dimensionless criteria specifying the nonequilibrium state of the material and the heat propagation character have been used to specify application regions of individual modes of heat propagation. The described microscale heat...

Heat transfer processes during high velocity oxy-fuel (HVOF) deposition of WC coatings are studied. Experiments were conducted with temperature measurement in the substrate by thermocouples. A designed 2D computer simulation model of the spraying process with a moving torch is fitted to match the experimentally obtained temperature evolution. The r...

Heat transfer processes during high velocity oxy-fuel (HVOF) deposition of WC coatings are studied. Experiments were conducted with temperature measurement in the substrate by thermocouples. A designed 2D computer simulation model of the spraying process with a moving torch is fitted to match the experimentally obtained temperature evolution. The r...

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