Jerzy Kaleta | Wrocław University of Technology (original) (raw)

Papers by Jerzy Kaleta

Acta Physica Polonica A, Feb 1, 2019

The microstructure, magnetic and mechanical properties of the annealed at 1430 K Ni50Mn25Ga20Gd5 ... more The microstructure, magnetic and mechanical properties of the annealed at 1430 K Ni50Mn25Ga20Gd5 (at.%) magnetic shape memory alloy were studied. The Ni50Mn25Ga20Gd5 ingot was prepared in a bulk form by arcmelting method. Scanning electron microscopy supported by atomic force microscopy investigations confirmed a dual-phase microstructure of the studied alloy characterized by Gd-poor and Gd-rich phases. Temperature dependence of magnetic magnetization M (T) measured at high (µ0H = 2 T) and low (µ0H = 0.25 T) value of external magnetic fields revealed that the fabricated material undergoes reversible martensitic transition close to the room temperature. The Curie temperature for the investigated material calculated from the M (T) curve measured in zero-field cooled mode is 377 K. Mechanical properties of the Ni50Mn25Ga20Gd5 alloy investigated by the means of a series of nanoindentation tests allowed to separate hardness for the Gd-poor (435 HV) and Gd-rich (562 HV) phase.

Journal of Rare Earths, Nov 1, 2019

Polycrystalline Ni 50 Mn 25 Ga 20 Gd 5 (at.%) magnetic shape memory alloy was investigated in the... more Polycrystalline Ni 50 Mn 25 Ga 20 Gd 5 (at.%) magnetic shape memory alloy was investigated in the asprepared state and after annealing at 1430 K for 3 h. Microstructural analysis revealed dual-phase nature of the material with substantial distinction between Gd-rich and Gd-poor phases. Magnetic measurements performed in wide range of temperatures confirmed reversible martensitic transformation in the annealed sample undergoing close to the room temperature. When it comes to the magnetic transition, the Curie temperature of the investigated alloy remained approximately unchanged at 370 K. Topography investigations conducted on the Atomic Force Microscope in contact mode allowed to measure 8 mm difference between minimum and maximum point of the martensite profile. The results from a series of nanoindentation tests shown that hardness of the Gd-rich phase is 23% to 35% higher than hardness of the Gd-poor phase, depending on the annealing state.

Acta Physica Polonica A, Feb 1, 2019

In recent years, amorphous and nanocrystalline Fe-based alloys, due to their unique soft magnetic... more In recent years, amorphous and nanocrystalline Fe-based alloys, due to their unique soft magnetic properties, have emerged as one of the most promising group of modern materials for various electric applications. This work presents microstructure and AC/DC magnetic properties of the NANOPERM-type material. The as-quenched amorphous Fe76Mo8Cu1B15 alloy was prepared by rapid quenching method in a form of 10 mm wide and 0.025 mm thick ribbon. Partial nanocrystallization was obtained by subsequent annealing of amorphous precursor at 783 K for 30 min. Microstructure investigation of annealed sample confirmed precipitation of α-Fe nanograins dispersed in amorphous matrix. In order to assess soft magnetic properties of fabricated material the dependences of core losses versus frequency (50 Hz-20 kHz) at room temperature were established, together with eddy currents, hysteresis, and anomalous losses coefficients separation. The frequency dependent correlation between real and imaginary part of permeability was also presented. Moreover, DC hysteresis loops of both as-quenched and annealed alloy were recorded in temperature range from 200 K to 400 K.

Journal of Magnetism and Magnetic Materials, Apr 1, 2019

The present study is focused on the influence of Ti and Gd doping at the Ga site on the microstru... more The present study is focused on the influence of Ti and Gd doping at the Ga site on the microstructure, magnetic and mechanical properties of the polycrystalline Ni 50 Mn 25 Ga 20-x Z x (x = 0 or 5, Z = Gd, Ti) magnetic shape memory alloys. Microstructure investigations show that reference Ni 50 Mn 25 Ga 25 and Ti-doped alloys, both in the as-cast and annealed state, are single phase materials, whereas Gd-doped sample reveals dendritic dual-phase structure with substantial distinction between Gd-rich and Gd-poor regions. Thermomagnetic measurements expose reversible martensitic transition in the Ni 50 Mn 25 Ga 25 and Ni 50 Mn 25 Ga 20 Ti 5 alloys, where Ti addition to NiMnGa composition leads to the decrease of phase transformation temperature from T M = 193 K for reference sample to T M = 172.5 K for Ti-doped material. Furthermore, the Ni 50 Mn 25 Ga 20 Gd 5 alloy does not experience fully martensitic transition. Temperatures of magnetic transformation also varies with chemical composition and equals to 379 K, 318 K and 370 K for the annealed Ni 50 Mn 25 Ga 25 , Ni 50 Mn 25 Ga 20 Ti 5 and Ni 50 Mn 25 Ga 20 Gd 5 alloy, respectively. Mechanical properties investigation based on the nanoindentation measurements shows beneficial influence of doping elements on material hardness. In addition, planar distributions of hardness allow to deconvolute mechanical properties of each individual phase of the Ni 50 Mn 25 Ga 20 Gd 5 alloy.

International Journal of Refrigeration-revue Internationale Du Froid, 2019

In this paper, a novel magnetoelectric laminated composite system consisting of a one layer of lo... more In this paper, a novel magnetoelectric laminated composite system consisting of a one layer of longitudinally polarized piezoelectric material sandwiched between two layers of transversally magnetized Terfenol-D magnetostrictive composite was presented. Terfenol-D composites were fabricated by embedding and aligning Terfenol-D particles with a size distribution of 5-300 μm in a Epolam 2015 epoxy matrix with volume fraction 0.7. Their quasistatic and dynamic magnetic and magnetomechanical properties were measured as functions of magnetic field. The PZT material was a commercially available material which was supplied by Smart Material company. The P1 type of micro fiber composite (MFC) was chosen. Behavior of this hybrid material in a variety of external magnetic field directions was investigated. Based on the obtained results, it was found that the prepared composite material exhibits magneto-electric effect in the case of work in a variable magnetic field.

Springer eBooks, 1991

The present paper deals with cyclic properties and hysteresis energy accumulation occurring in fa... more The present paper deals with cyclic properties and hysteresis energy accumulation occurring in fatigue tested sintered steels. The specimens were subjected to sinusoidal uniaxial tension-compression (R = -1) within a wide range of LCF/HCF loading up to the fatigue limit. In each test determined were successively: plastic deformation e p , hysteresis energy ΔW and total energy W accumulated throughout the process. A new method was applied to determine e p , ΔW and W. The experimental results served a basis for verifying the models of plastic strain e p , energy ΔW and W.

Materials, Nov 20, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Aug 1, 1997

Abstract The essential aim of this paper is the description of cyclic properties of metastable au... more Abstract The essential aim of this paper is the description of cyclic properties of metastable austenic steel with martensitic transformation induced by cyclic plastic deformation. The main problem is the model of σ-e hysteresis loop as well as the phenomenon of cyclic softening. The original model of elasto-plastic body was applied to make a description. The model includes the appearance of cyclic plasticity limit and strain e 1 corresponding to the inflexion point at CSS curve. This point separates the one phase range (austenite) from the two phase range (austenite + martensite). The plastic deformation e 1 was accepted as the material constant and named the cyclic limit of martensitic transformation. The experimental fatigue investigations of high nickel alloy steel of the type AISI 304 were carried to identify the model. The experiments were performed for the controlled plastic deformation ampliture value e p = constant. The results confirmed adequacy of the accepted model.

Journal of Non-Crystalline Solids

Surface and Coatings Technology

Volume 5: High-Pressure Technology; ASME Nondestructive Evaluation, Diagnosis and Prognosis Division (NDPD); Rudy Scavuzzo Student Paper Symposium and 26th Annual Student Paper Competition, 2018

The main purpose of the work was development of high-pressure composite vessel for hydrogen stora... more The main purpose of the work was development of high-pressure composite vessel for hydrogen storage (type IV, CFRC) with an integrated Structural Health Monitoring (SHM) system, based on optical fiber sensors. It has been assumed that this NDE system should provide for continuous and reliable monitoring of the structure during its long operation and enable estimation of degradation degree of the composite vessel load-carrying layer, and by that determination of its safe operation period. Showing suitability of the system for control of the vessels manufacturing technology and fulfilling the requirements of vessel certification standards has been also considered essential. It has been expected, that reaching the work goals required application of measurement methods based at fibre optic sensors with particular consideration for the Fibre Bragg Gratings (FBG). These transducers allowed for integration with the monitored object and were embedded in the composite material structure with...

Polymer Composites, 2022

Automated tape layup (ATL) has been used extensively for manufacturing composites laminates using... more Automated tape layup (ATL) has been used extensively for manufacturing composites laminates using unidirectional prepregs for high‐performance industries like aerospace. Residual stress is one of the defects that adversely affect the layup quality. These stresses affect geometrical tolerances in the form of distortion of the final product and are found to have a detrimental impact on the mechanical properties. In‐line monitoring of such defects will help in productivity increase and achieving a reliable process control. The aim of the present work is to demonstrate the feasibility of fiber Bragg grating sensors for monitoring residual strains. FBGs are embedded inside a thermoplastic UD laminate. Temperature and strain discrimination is performed to recognize intermittent residual strains during the layup. Finally, intermittent residual strain is used to develop an understanding of the global residual strain. Effect of selective process parameter on residual stress formation and the...

Composite Structures, 2018

The work presents the methodology of displacement and strain measurements (in type IV composite h... more The work presents the methodology of displacement and strain measurements (in type IV composite high pressure hydrogen and methane storage vessels in areas of the gaseous fuel cell vehicle. The research was conducted in vessels with so called programmed defects in the form of notches and delamination. The complementary optical methods, namely: optical fibre sensing based on Bragg gratings (FBG) and digital image correlation (DIC) method were used for performing local and full-field displacement/strain measurements respectively. It has been shown that DIC can be successfully applied as the method for defect identification in full field of view and that it can support an optimal localization of FBG sensors and their calibration. As FBG sensors are devoted to be integrated with the vessel structure, the proposed methodology constitutes a solution to the difficult problem of building an efficient Structural Health Monitoring (SHM) system for composite high pressure vessels for gaseous fuels. At the same time the measurement data from both systems supports calibration of numerical models of the vessels.

Mechatronics 2013, 2014

The paper presents an original design of 3-segments adaptronic analogue of units of mammal’s vert... more The paper presents an original design of 3-segments adaptronic analogue of units of mammal’s vertebrae based on 8 actuators using dielectric electro-active polymer (DEAP). The way of preparation took into account the tendency of the DEAP material to local breakdowns, caused by degradation of the internal structure. The cross effects of phase response on a given electrical stimulus under high voltage were identified as well. The degrees of freedom of the analogue segments were determined, taking into account biological significance of vertebral endplates which a simplified form is included in the model. The work is to propose a bio-inspired techniques to build robots with many degrees of freedom using DEAP materials.

Long-term safety of using pipelines is a major problem for their owners and exploiters. This appl... more Long-term safety of using pipelines is a major problem for their owners and exploiters. This applies to both gas pipelines, pipelines to crude oil transport, as well as industrial pipelines in chemical plants (eg. the transportation of chlorine, ammonia or hydrogen) and power plants (eg. for transport of water vapour under high pressure, flue gas in desulphurization systems – Fig. 1, etc.). Many times even a small failure (eg. leak) causes a measurable impact on the environment (possible contamination) as well as economical for the owner of the pipeline (temporary exclusion from service, the loss of transmitted material, compensation for environmental pollution, reconstruction of infrastructure, etc.) [1,2]. The complexity of static forces, unpredictable loads, degradation of materials and, above all, pose a significant length of the pipelines and cause a lot of problems that the opinions formulated by the engineers controlling the technical state of the object are based on uncertai...

Acta Physica Polonica A, Feb 1, 2019

The microstructure, magnetic and mechanical properties of the annealed at 1430 K Ni50Mn25Ga20Gd5 ... more The microstructure, magnetic and mechanical properties of the annealed at 1430 K Ni50Mn25Ga20Gd5 (at.%) magnetic shape memory alloy were studied. The Ni50Mn25Ga20Gd5 ingot was prepared in a bulk form by arcmelting method. Scanning electron microscopy supported by atomic force microscopy investigations confirmed a dual-phase microstructure of the studied alloy characterized by Gd-poor and Gd-rich phases. Temperature dependence of magnetic magnetization M (T) measured at high (µ0H = 2 T) and low (µ0H = 0.25 T) value of external magnetic fields revealed that the fabricated material undergoes reversible martensitic transition close to the room temperature. The Curie temperature for the investigated material calculated from the M (T) curve measured in zero-field cooled mode is 377 K. Mechanical properties of the Ni50Mn25Ga20Gd5 alloy investigated by the means of a series of nanoindentation tests allowed to separate hardness for the Gd-poor (435 HV) and Gd-rich (562 HV) phase.

Journal of Rare Earths, Nov 1, 2019

Polycrystalline Ni 50 Mn 25 Ga 20 Gd 5 (at.%) magnetic shape memory alloy was investigated in the... more Polycrystalline Ni 50 Mn 25 Ga 20 Gd 5 (at.%) magnetic shape memory alloy was investigated in the asprepared state and after annealing at 1430 K for 3 h. Microstructural analysis revealed dual-phase nature of the material with substantial distinction between Gd-rich and Gd-poor phases. Magnetic measurements performed in wide range of temperatures confirmed reversible martensitic transformation in the annealed sample undergoing close to the room temperature. When it comes to the magnetic transition, the Curie temperature of the investigated alloy remained approximately unchanged at 370 K. Topography investigations conducted on the Atomic Force Microscope in contact mode allowed to measure 8 mm difference between minimum and maximum point of the martensite profile. The results from a series of nanoindentation tests shown that hardness of the Gd-rich phase is 23% to 35% higher than hardness of the Gd-poor phase, depending on the annealing state.

Acta Physica Polonica A, Feb 1, 2019

In recent years, amorphous and nanocrystalline Fe-based alloys, due to their unique soft magnetic... more In recent years, amorphous and nanocrystalline Fe-based alloys, due to their unique soft magnetic properties, have emerged as one of the most promising group of modern materials for various electric applications. This work presents microstructure and AC/DC magnetic properties of the NANOPERM-type material. The as-quenched amorphous Fe76Mo8Cu1B15 alloy was prepared by rapid quenching method in a form of 10 mm wide and 0.025 mm thick ribbon. Partial nanocrystallization was obtained by subsequent annealing of amorphous precursor at 783 K for 30 min. Microstructure investigation of annealed sample confirmed precipitation of α-Fe nanograins dispersed in amorphous matrix. In order to assess soft magnetic properties of fabricated material the dependences of core losses versus frequency (50 Hz-20 kHz) at room temperature were established, together with eddy currents, hysteresis, and anomalous losses coefficients separation. The frequency dependent correlation between real and imaginary part of permeability was also presented. Moreover, DC hysteresis loops of both as-quenched and annealed alloy were recorded in temperature range from 200 K to 400 K.

Journal of Magnetism and Magnetic Materials, Apr 1, 2019

The present study is focused on the influence of Ti and Gd doping at the Ga site on the microstru... more The present study is focused on the influence of Ti and Gd doping at the Ga site on the microstructure, magnetic and mechanical properties of the polycrystalline Ni 50 Mn 25 Ga 20-x Z x (x = 0 or 5, Z = Gd, Ti) magnetic shape memory alloys. Microstructure investigations show that reference Ni 50 Mn 25 Ga 25 and Ti-doped alloys, both in the as-cast and annealed state, are single phase materials, whereas Gd-doped sample reveals dendritic dual-phase structure with substantial distinction between Gd-rich and Gd-poor regions. Thermomagnetic measurements expose reversible martensitic transition in the Ni 50 Mn 25 Ga 25 and Ni 50 Mn 25 Ga 20 Ti 5 alloys, where Ti addition to NiMnGa composition leads to the decrease of phase transformation temperature from T M = 193 K for reference sample to T M = 172.5 K for Ti-doped material. Furthermore, the Ni 50 Mn 25 Ga 20 Gd 5 alloy does not experience fully martensitic transition. Temperatures of magnetic transformation also varies with chemical composition and equals to 379 K, 318 K and 370 K for the annealed Ni 50 Mn 25 Ga 25 , Ni 50 Mn 25 Ga 20 Ti 5 and Ni 50 Mn 25 Ga 20 Gd 5 alloy, respectively. Mechanical properties investigation based on the nanoindentation measurements shows beneficial influence of doping elements on material hardness. In addition, planar distributions of hardness allow to deconvolute mechanical properties of each individual phase of the Ni 50 Mn 25 Ga 20 Gd 5 alloy.

International Journal of Refrigeration-revue Internationale Du Froid, 2019

In this paper, a novel magnetoelectric laminated composite system consisting of a one layer of lo... more In this paper, a novel magnetoelectric laminated composite system consisting of a one layer of longitudinally polarized piezoelectric material sandwiched between two layers of transversally magnetized Terfenol-D magnetostrictive composite was presented. Terfenol-D composites were fabricated by embedding and aligning Terfenol-D particles with a size distribution of 5-300 μm in a Epolam 2015 epoxy matrix with volume fraction 0.7. Their quasistatic and dynamic magnetic and magnetomechanical properties were measured as functions of magnetic field. The PZT material was a commercially available material which was supplied by Smart Material company. The P1 type of micro fiber composite (MFC) was chosen. Behavior of this hybrid material in a variety of external magnetic field directions was investigated. Based on the obtained results, it was found that the prepared composite material exhibits magneto-electric effect in the case of work in a variable magnetic field.

Springer eBooks, 1991

The present paper deals with cyclic properties and hysteresis energy accumulation occurring in fa... more The present paper deals with cyclic properties and hysteresis energy accumulation occurring in fatigue tested sintered steels. The specimens were subjected to sinusoidal uniaxial tension-compression (R = -1) within a wide range of LCF/HCF loading up to the fatigue limit. In each test determined were successively: plastic deformation e p , hysteresis energy ΔW and total energy W accumulated throughout the process. A new method was applied to determine e p , ΔW and W. The experimental results served a basis for verifying the models of plastic strain e p , energy ΔW and W.

Materials, Nov 20, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Aug 1, 1997

Abstract The essential aim of this paper is the description of cyclic properties of metastable au... more Abstract The essential aim of this paper is the description of cyclic properties of metastable austenic steel with martensitic transformation induced by cyclic plastic deformation. The main problem is the model of σ-e hysteresis loop as well as the phenomenon of cyclic softening. The original model of elasto-plastic body was applied to make a description. The model includes the appearance of cyclic plasticity limit and strain e 1 corresponding to the inflexion point at CSS curve. This point separates the one phase range (austenite) from the two phase range (austenite + martensite). The plastic deformation e 1 was accepted as the material constant and named the cyclic limit of martensitic transformation. The experimental fatigue investigations of high nickel alloy steel of the type AISI 304 were carried to identify the model. The experiments were performed for the controlled plastic deformation ampliture value e p = constant. The results confirmed adequacy of the accepted model.

Journal of Non-Crystalline Solids

Surface and Coatings Technology

Volume 5: High-Pressure Technology; ASME Nondestructive Evaluation, Diagnosis and Prognosis Division (NDPD); Rudy Scavuzzo Student Paper Symposium and 26th Annual Student Paper Competition, 2018

The main purpose of the work was development of high-pressure composite vessel for hydrogen stora... more The main purpose of the work was development of high-pressure composite vessel for hydrogen storage (type IV, CFRC) with an integrated Structural Health Monitoring (SHM) system, based on optical fiber sensors. It has been assumed that this NDE system should provide for continuous and reliable monitoring of the structure during its long operation and enable estimation of degradation degree of the composite vessel load-carrying layer, and by that determination of its safe operation period. Showing suitability of the system for control of the vessels manufacturing technology and fulfilling the requirements of vessel certification standards has been also considered essential. It has been expected, that reaching the work goals required application of measurement methods based at fibre optic sensors with particular consideration for the Fibre Bragg Gratings (FBG). These transducers allowed for integration with the monitored object and were embedded in the composite material structure with...

Polymer Composites, 2022

Automated tape layup (ATL) has been used extensively for manufacturing composites laminates using... more Automated tape layup (ATL) has been used extensively for manufacturing composites laminates using unidirectional prepregs for high‐performance industries like aerospace. Residual stress is one of the defects that adversely affect the layup quality. These stresses affect geometrical tolerances in the form of distortion of the final product and are found to have a detrimental impact on the mechanical properties. In‐line monitoring of such defects will help in productivity increase and achieving a reliable process control. The aim of the present work is to demonstrate the feasibility of fiber Bragg grating sensors for monitoring residual strains. FBGs are embedded inside a thermoplastic UD laminate. Temperature and strain discrimination is performed to recognize intermittent residual strains during the layup. Finally, intermittent residual strain is used to develop an understanding of the global residual strain. Effect of selective process parameter on residual stress formation and the...

Composite Structures, 2018

The work presents the methodology of displacement and strain measurements (in type IV composite h... more The work presents the methodology of displacement and strain measurements (in type IV composite high pressure hydrogen and methane storage vessels in areas of the gaseous fuel cell vehicle. The research was conducted in vessels with so called programmed defects in the form of notches and delamination. The complementary optical methods, namely: optical fibre sensing based on Bragg gratings (FBG) and digital image correlation (DIC) method were used for performing local and full-field displacement/strain measurements respectively. It has been shown that DIC can be successfully applied as the method for defect identification in full field of view and that it can support an optimal localization of FBG sensors and their calibration. As FBG sensors are devoted to be integrated with the vessel structure, the proposed methodology constitutes a solution to the difficult problem of building an efficient Structural Health Monitoring (SHM) system for composite high pressure vessels for gaseous fuels. At the same time the measurement data from both systems supports calibration of numerical models of the vessels.

Mechatronics 2013, 2014

The paper presents an original design of 3-segments adaptronic analogue of units of mammal’s vert... more The paper presents an original design of 3-segments adaptronic analogue of units of mammal’s vertebrae based on 8 actuators using dielectric electro-active polymer (DEAP). The way of preparation took into account the tendency of the DEAP material to local breakdowns, caused by degradation of the internal structure. The cross effects of phase response on a given electrical stimulus under high voltage were identified as well. The degrees of freedom of the analogue segments were determined, taking into account biological significance of vertebral endplates which a simplified form is included in the model. The work is to propose a bio-inspired techniques to build robots with many degrees of freedom using DEAP materials.

Long-term safety of using pipelines is a major problem for their owners and exploiters. This appl... more Long-term safety of using pipelines is a major problem for their owners and exploiters. This applies to both gas pipelines, pipelines to crude oil transport, as well as industrial pipelines in chemical plants (eg. the transportation of chlorine, ammonia or hydrogen) and power plants (eg. for transport of water vapour under high pressure, flue gas in desulphurization systems – Fig. 1, etc.). Many times even a small failure (eg. leak) causes a measurable impact on the environment (possible contamination) as well as economical for the owner of the pipeline (temporary exclusion from service, the loss of transmitted material, compensation for environmental pollution, reconstruction of infrastructure, etc.) [1,2]. The complexity of static forces, unpredictable loads, degradation of materials and, above all, pose a significant length of the pipelines and cause a lot of problems that the opinions formulated by the engineers controlling the technical state of the object are based on uncertai...