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1

Tribological Wear Behaviour of Electrical Contacts Made from AgNi10 Composite

Richert M. W., Boczkal G., Hotloś A., Pałka P., Karpiński M.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 4

2007--2013

EN

The effect of tribological wear of contacts made from an AgNi10 alloy on microstructure and electrical properties was investigated. The contacts were tested in duty cycles loaded with alternating current of 10A intensity. With this value of the current, intensive arcing of contacts occurred. The contacts were tested in the range of 125 to 500 thousand cycles. The contacting surfaces were reported to suffer a high degree of wear, but electrical resistance of the contact system remained stable.

2

Electrical contacts produced from AgSnBi alloy by combined method of CEC + HE

Boczkal G., Richert M. W., Hotloś A., Pałka P., Wiewióra J.

Rudy i Metale Nieżelazne Recykling

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2016

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R. 61, nr 4

164--167

EN

The structure and tribological properties of AgSnBi electrical contacts were investigated. An alternative method for the manufacture of electrical contacts from the AgSnBi powder has been used. Its essence consists in consolidation of material by two SPD methods, i.e. cyclic extrusion-compression and hydrostatic extrusion. High degree of the consolidation of samples was achieved along with the nanometric structure. Studies have revealed satisfactory electrical properties stable after multiple cycles, although a tendency to self-sticking (welding) of contacts was also noted.

PL

W pracy badano strukturę i zużycie trybologiczne styków wykonanych ze stopu AgSnBi. Zastosowano alternatywną metodę wytwarzania, polegającą na użyciu dwóch metod: cyklicznego wyciskania ściskającego (CWS), a następnie wyciskania hydrostatycznego (HE). Stwierdzono bardzo dobry stopień skonsolidowania próbek oraz występowanie struktury nanometrycznej. Badania wykazały dobre własności elektryczne nie ulegające zmianie po dużej ilości cykli, jednakże zauważono tendencję do samoistnego sklejania się styków.

3

Processing of Copper by Hydrostatic Extrusion – Studies of Microstructure and Properties

Leszczyńska-Madej B., Richert M. W., Nejman I., Zawadzka P.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1575--1580

EN

The present study attempts to apply HE to 99.99% pure copper. The microstructure of the samples was investigated by both light microscopy and scanning transmission electron microscopy (STEM). Additionally, the microhardness was measured, the tensile test was made, and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns, misorientation was determined. The obtained results show that microstructure of copper deformed by hydrostatic extrusion (HE) is rather inhomogeneous. The regions strongly deformed with high dislocation density exist near cells and grains/subgrains free of dislocations. The measurements of the grain size have revealed that the sample with an initial in annealed-state grain size of about 250 μm had this grain size reduced to below 0.35μm when it was deformed by HE to the strain ε=2.91. The microhardness and UTS are stable within the whole investigated range of deformation.

4

Wpływ procesu wytwarzania na mikrostrukturę styków AgSn7,5Bi0,4

Leszczyńska-Madej B., Richert M.W.

Rudy i Metale Nieżelazne Recykling

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2015

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R. 60, nr 12

741--748

PL

Do konsolidacji proszku AgSnBi wykorzystano metodę Cyklicznego Wyciskania Ściskającego (CWS), co umożliwiło uzyskanie litego materiału. Tak wytworzony materiał odkształcono w procesie wyciskania hydrostatycznego (HE), a następnie w procesie kucia wytworzono styki elektryczne. Przeprowadzono badania mikrostruktury i mikrotwardości próbek na każdym etapie odkształcenia.

EN

The Reciprocating Extrusion (Cyclic Extrusion Compression — CEC) process was applied to the consolidation of silver powder AgSnBi leading to the bulk material formation. Continue process of deformation of consolidated powder by Hydrostatic Extrusion (HE) and then by forging the electrical contacts were produced. Microstructure and microhardness were investigated on the every stage of deformation showing development of process consolidation.

5

Styki elektryczne AgSnBi wytwarzane kombinowaną metodą CWS + HE

Boczkal G., Richert M.W., Hotloś A., Pałka P., Wiewióra J.

Rudy i Metale Nieżelazne Recykling

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2015

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R. 60, nr 11

637--640

PL

W artykule badano strukturę i zużycie trybologiczne styków wykonanych ze stopu AgSnBi. Zastosowano alternatywną metodę wytwarzania, polegającą na użyciu dwóch metod: cyklicznego wyciskania ściskającego (CWS), a następnie wyciskania hydrostatycznego (HE). Stwierdzono bardzo dobry stopień skonsolidowania próbek oraz występowanie struktury nanometrycznej. Badania wykazały dobre własności elektryczne nie ulegające zmianie po dużej ilości cykli, jednakże zauważono tendencję do samoistnego sklejania się styków.

EN

The structure and tribological properties of AgSnBi electrical contacts was investigated. An alternative method of producing material with AgSnBi powder is consolidation by using two SPD methods: cyclic extrusion compression and hydrostatic extrusion. Very good consolidation of samples and the occurrence of a nanometric structure was observed. The studies revealed good electrical properties that do not change even after multiple cycles, however, a tendency to self-sticking of contacts was noted.

6

Effect Of Severe Plastic Deformation On Microstructure Evolution Of Pure Aluminium

Leszczyńska-Madej B., Richert M. W., Perek-Nowak M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1437--1440

EN

Processes of severe plastic deformation (SPD) are defined as a group of metalworking techniques in which a very large plastic strain is imposed on a bulk material in order to make an ultra-fine grained metal. The present study attempts to apply Equal-Channel Angular Pressing (ECAP), Hydrostatic Extrusion (HE) and combination of ECAP and HE to 99.5% pure aluminium. ECAP process was realized at room temperature for 16 passes through route Bc using a die having an angle of 90°. Hydrostatic extrusion process was performed with cumulative strain of 2.68 to attain finally wire diameter of d = 3 mm. The microstructure of the samples was investigated by means of transmission and scanning electron microscopy. Additionally, the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. The measured grain/subgrain size show, that regardless the mode of deformation process (ECAP, HE or combination of ECAP and HE processes), grain size is maintained at a similar level – equal to d = 0.55-0.59 μm. A combination of ECAP and HE has achieved better properties than either single process and show to be a promising procedure for manufacturing bulk UFG aluminium.

7

Powłoki użytkowe na narzędziach i częściach maszyn dla przemysłu metali nieżelaznych

Richert M. W., Zawadzka M.

Obróbka Plastyczna Metali

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2014

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T. 25, nr 1

5--26

PL

W artykule przedstawiono przegląd literaturowy oraz badania własne dotyczące powłok ochronnych stosowanych na narzędziach i częściach maszyn dla przemysłu metali nieżelaznych. Pokazano, że dobór odpowiedniej metody wytwarzania jak i składu chemicznego powłoki pozwala w znacznym stopniu zwiększyć trwałość pokrywanego elementu. Omówiono także wpływ parametrów procesu osadzania na jakość wytwarzanych powłok.

EN

In the paper the review of literature and own investigations concerning the protective coatings deposited at tools and parts of equipment using in the non-ferrous metals industry have been presented. It has been shown that choice of proper method of production and also the chemical composition of coating allowing in large step increase the durability of the deposited element. The influence of process deposition parameters on the quality of coatings was also discussed.

8

AgSnBi powder consolidated by CEC reciprocal extrusion

Richert M. W., Richert J., Leszczyńska-Madej B., Kuczek Ł., Wzorek Ł.

Archives of Civil and Mechanical Engineering

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2014

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Vol. 14, no. 4

580--585

EN

The reciprocating extrusion (cyclic extrusion compression – CEC) process was applied to the consolidation of silver powder AgSnBi leading to the bulk material formation. Continue process of deformation by hydrostatic extrusion and then by forging the electrical contacts were produced. Microstructure and microhardness were investigated in every stage of deformation showing development of process consolidation. The relative density of material was evaluated on the base of voids existing inside the microstructure.

9

The effect of reciprocating extrusion (CEC) on the consolidated silver powders microstructure

Richert M. W., Richert J., Hotloś A., Mroczkowski M., Tokarski T.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 1

73-75

EN

The microstructure and properties investigations silver powders consolidated by cyclic extrusion compression (CEC) were performed. The AgSnBi and AgNi powders using for electrical contacts were investigated. The observation by using optical microscopy (MO) and transmission electron microscopy (TEM) were apply. The strong diminishing of microstructure inside the consolidated granules were found. This phenomenon cause microhardness increase, restricted by material porosity.

PL

W pracy przedstawiono badania mikrostruktury i własności proszków srebra konsolidowanych metodą cyklicznego wyciskania ściskającego – CWS. Badania objęły proszki AgSnBi oraz AgNi stosowane na styki elektryczne. Przeprowadzono obserwacje przy użyciu mikroskopu optycznego (MO) oraz transmisyjnego mikroskopu elektronowego (TEM). Stwierdzono silne rozdrobnienie mikrostruktury wewnątrz konsolidowanych granul proszków. Spowodowało to wzrost mikrotwardości, ograniczony porowatością materiału.

10

Microstructure characterization of chromium carbides coatings deposited by thermal spraying processes

Richert M. W., Książek M., Pałka P., Wawrzyniak S., Grzelka R., Płońska-Niżnik K.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 1

108--112

EN

Purpose: The Cr3C2-NiCr coatings were deposited by plasma spraying (PS) and high velocity oxy-fuel (HVOF) processes. The objective of the work concerns characterization of microstructure of sprayed coatings. In the investigated samples, apart from Cr3C2 carbide particles, the carbides Cr7C3 were also present according to the reported through X-ray diffraction analyses. It is likely that Cr7C3 carbides were formed thorough decarburization of Cr3C2. The microstructure of the thermal sprayed Cr3C2-NiCr coatings was characterized by optical (MO), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The fine-grained and nano-crystalline microstructure was found in the investigated coatings. The microhardness of coatings was measured. It was found that the coatings deposited in HVOF process have higher microhardnes than the plasma spraying one. The formation of chromium carbide phases in the coatings was discussed based on the microstructure observation results. Design/methodology/approach: The investigations of coating microstructure by optical microscopy (MO) Olympus GX51, scanning electron microscopy STEREOSCAN 420 and transmission electron microscopy JEM2010 ARP (TEM) were performed. The examination of phase consistence was determined by Brucker D8 Discover - Advance diffractometer with copper tubing. The microhardness of coatings was measured by Vickers method. Findings: The microstructures of Cr3C2-NiCr coatings were observed and analyzed. On the base of the microstructure investigations and contend of the chromium carbides the mechanism of thermal sprayed coating formation was discussed. Practical implications: The performed investigations contribute to the improvement of microstructure and properties of thermal spraying coatings used in the industrial applications. Originality/value: It was assumed that thermal spraying processes are able to form nano-crystalline microstructure of the chromium carbide coatings.

11

The microstructure and properties of hydrostatically extruded polycrystalline aluminium Al99.5

Richert M. W., Leszczyńska-Madej B., Pachla W., Skiba J.

Archives of Metallurgy and Materials

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2012

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Vol. 57, iss. 4

911-917

EN

The changes of Al99.5 microstructure and properties deformed by hydrostatic extrusion process in the conditions of constant strain rate (1.35x10² s &sup-1;) and variable deformation (Φ= 1.44 divide; 2.85) were investigated. The samples were investigated by means both optical (LM) and transmission electron microscopy (TEM). The size of subgrain was statistically measured by mean chord. To establish the influence of hydrostatic extrusion on the properties of the polycrystalline aluminium Al99.5, the microhardness was measured and the tensile test was performed. The bands and shear bands were the characteristic feature of the sample microstructure. TEM micrographs show equiaxed subgrains with small density of dislocations inside. The measured subgrain size was placed in the range of d = 550 divide; 650 nm. The mechanical properties of polycrystalline aluminium Al99.5 keep almost the same level in the investigated range of deformations. It was found that after the initial deformation microhardness and yield stress nearly twice increase in comparison to the initial state. The greatest increase of properties was observed after deformation Φ = 1.44. Then the mechanical properties stabilize.

PL

W pracy przedstawiono wyniki badań mikrostruktury i własności wyciskanego hydrostatycznie polikrystalicznego aluminium Al99.5. Proces wyciskania hydrostatycznego był realizowany w warunkach stałej prędkości odkształcenia wynoszącej 1,35x10 ² s &sup-1; w zakresie odkształceń rzeczywistych Φ = 1,44 ÷ 2,85. Tak odkształcone próbki poddano obserwacjom przy zastosowaniu mikroskopu świetlnego (MO) oraz transmisyjnego mikroskopu elektronowego (TEM), zmierzono mikrotwardość oraz przeprowadzono próbę jednoosiowego rozciągania. Dodatkowo stosując parametr średniej cięciwy dokonano statystycznej analizy utworzonych w mikrostrukturze podziarn. Charakterystyczna cecha wyciskanego hydrostatycznie aluminium są licznie występujące pasma i pasma ścinania, które widoczne są zarówno na przekrojach wzdłużnych, jak i poprzecznych próbek. Wyniki uzyskane przy zastosowaniu transmisyjnego mikroskopu elektronowego wykazały występowanie struktury podziarnowej. Obserwowane podziarna maja niemal równoosiowy kształt. Średnia zmierzona wielkość podziarna mieści sie w zakresie d = 550 divide; 650nm. Wyznaczone własności mechaniczne wskazują na ponad dwukrotny wzrost w odniesieniu do stanu wyjściowego przed odkształceniem. Przeprowadzone badania dowodzą, ze polikrystaliczne aluminium Al99,5 odkształcane przy stałej prędkości odkształcenia wynoszącej 1,35x10² s&sup-1; w zakresie odkształceń rzeczywistych Φ = 1,44 ÷ 2,85 nie wykazuje istotnych zmian zarówno w mikrostrukturze, jak i w poziomie umocnienia.

12

The deposition of WC-Co coatings by EBPVD technique

Richert M. W., Mazurkiewicz A., Smolik J. A.

Archives of Metallurgy and Materials

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2012

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Vol. 57, iss. 2

511-515

EN

The WC-Co carbides are widely used to deposit protective coatings on engineering surfaces against abrasion, erosion and other forms of wear existence. The nanostructure coatings offer high strength, a low friction coefficient and chemical and thermal stability. WCo coatings were deposited using EBPVD technique realized in original technological process implemented in the hybrid multisource device, produced in the Institute for Sustainable Technologies - National Research Institute in Radom (Poland). The different kind of precursor sources was used. Depending on the source of precursors nanostructure of coatings forms continuous film or consist from nano-carbides. Nanocrystalline WC-Co coatings show hardness in the range of 510-1266 HV. The microstructure of coatings were observed by transmission electron microscopy (TEM). The phase consistence were determined byBrucker D8 Discover-Advance Diffractometer. The paper presents the original technological equipment, methodology, and technological parameters for the creation of the nanocomposite coatings WC.

PL

Węgliki WC-Co są szeroko używane do osadzania na powierzchniach inżynierskich jako ochrona przeciwko tarciu, erozji i innym formom zużycia. Powłoki nanostrukturalne wykazują wysoka wytrzymałość, niski współczynnik tarcia oraz chemiczną i termiczną stabiność. Powłoki WC-Co zostały osadzane techniką EBPVD przy użyciu oryginalnego technologicznego procesu z hybrydowym źródłem prekursorów, w Instytucie Technologii Eksploatacji w Radomiu (Polska). Użyto różnego rodzaju źródeł prekursorów. W zależności od rodzaju użytego źródła prekursorów nanostrukturalne powłoki były zbudowane z ciągłych warstw lub z nano-weglików. Mikrotwardość nanokrystalicznych powłok mieściła się w zakresie 510-1266 μHV. Mikrostruktura powłok była obserwowana transmisyjnym mikroskopem elektronowym (TEM). Skład fazowy powłok określono za pomocą aparatu rentgenowskiego Brucker D8 Discover-Advance Diffractometer. Artykuł prezentuje oryginalne technologiczne urządzenie, metodologię i technologiczne parametry pozwalające na wytworzenie nanokompozytowej powłoki WC.

13

Microstructure of AgSnBi powder consolidated in reciprocating extrusion process

Richert M. W., Richert J., Hotloś A., Perek-Nowak M., Tokarski T., Skiba J.

Archives of Materials Science and Engineering

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2012

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Vol. 58, nr 2

120--124

EN

Purpose: The AgSnBi powder used for electrical contacts has been consolidated in the process of reciprocating extrusion (cyclic extrusion compression - CEC) in 2, 4, 8 and 16 CEC cycles at room temperature. It corresponds to the deformations: 2 CEC cycles - ϕ = 0.84, 4 CEC cycles - ϕ = 1.68, 8 CEC cycles - ϕ = 3.36 and 16 CEC cycles - ϕ = 6.72. The microstructure of consolidated powder has been characterized by optical microscopy (MO), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found characteristic granular microstructure with the oxides film at granular boundaries. Some voids and cracks were observed in consolidated samples, especially at higher magnifications. Inside the consolidated granules the nano-microstructure with nano - twins was found. Microhardness of AgSnBi after the consolidation by the CEC process achieved level of about 100-110 μHV. The microhardness of samples consolidated by CEC and then hydrostatically extruded increase of about 20 μHV units. Design/methodology/approach: The investigations of microstructure were performed by optical microscopy (MO) Olympus GX51, and scanning electron microscopy SU-70 with field emission gun thermally aided. The microhardness of consolidated samples was measured by Vickers method. Findings: The microstructures of consolidated AgSnBi powders were observed and analyzed. On the base of the microstructure and microhardness investigations the mechanisms of formation of bulk material from powder by severe plastic deformation (SPD) methods was discussed. Practical implications: The performed investigations contribute to the understanding of processes of deformation in the range of unconventional strains exerted by the SPD methods. The new way of consolidation of powders using to the production of electrical contacts was presented. Originality/value: It was assumed that AgSnBi powder consolidated by CEC and hydrostatic extrusion exhibited the nano-microstructure.

14

Nanostrukturalne powłoki na bazie węglika chromu Cr3C2 wytwarzane różnymi metodami PVD

Mazurkiewicz A., Richert M. W., Smolik J. A.

Problemy Eksploatacji

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2011

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nr 4

115-124

PL

W pracy przedstawiono badania mikrostruktury i twardości węglikowych powłok kompozytowych Cr3C2 - Ni/Cr otrzymanych czterema różnymi metodami PVD, w tym: natrysku plazmowego - Plasma Spraying, natrysku płomieniowego naddźwiękowego - Hot Velocity Oxygen Fuel (HVOF), metodą odparowania materiałów wiązką elektronową - Electron Beam (EB PVD) oraz metodą hybrydową będącą połączeniem odparowania materiałów wiązką elektronową oraz odparowania łukowego (Arc-EB PVD). Wykazano, że w metodach natryskowych, jak również w metodach plazmowych wykorzystujących proces odparowania materiału wiązką elektronów, w warunkach o zbliżonej energii procesu sprzyjających kształtowaniu powłok nanometrycznych następuje kształtowanie podobnej mikrostruktury. Twardość powłok kompozytowych Cr3C2 - Ni/Cr nie jest zależna jedynie od ich mikrostruktury, ale również istotnie zależy od metody ich wytwarzania.

EN

The paper presents the results of microstructure and hardness measurements for composite coatings Cr3C2 - i/Cr obtained by different surface treatment methods: Plasma Spraying, Hot Velocity Oxygen Fuel (HVOF), Electron Beam (EB PVD) and original hybrid surface treatment method as connection of Arc Evaporation and Electron Beam (Arc-EB PVD). Authors proved that during the deposition processes realised by Plasma Spraying and Electron Beam as well as by HVOF and hybrid method Arc-EB PVD, the energy of deposition processes are comparable, so in effect the comparable microstructures were obtained. Simultaneously was proved that the hardness of composite coatings Cr3C2 - Ni/Cr is not only depend on those microstructure but on the deposition method as well.

15

The wear resistance of thermal spray the tungsten and chromium carbides coatings

Richert M. W.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 47, nr 2

177--184

EN

Purpose: The objective of the work concerns of wear-resistance of different kinds of thermal spray coatings covering industrial fun blades. The coatings were sprayed onto the fun blades by Plasma Spraying and High Velocity Oxygen Fuel Spraying (HVOF) methods. The Cr3C2, WC and also its compositions were sprayed into the fun blades. The coatings were tested in industry conditions and the effect of influence of centrifugation industry emissions on the stage of the wearing after the exploitation was compared for deposited coatings. Design/methodology/approach: The investigations of coating microstructures by optical microscopy (MO) and transmission electron microscopy (TEM) were performed. The examination of fun blades after the exploitation and the analysis of the obtained results was correlated with the performed microstructure observations and microhardness data of coatings. Findings: The microstructures of Cr and W carbides coatings were observed and analyzed. The micro hardness of the sprayed coatings was compared. The coatings were evaluated from the point of view resistance against the wear. Practical implications: The performed investigations provide information, which kind of carbide coatings characterize the most wear resistance in the industrial conditions. Originality/value: It was assumed that HFOV coats have more uniform microstructure, higher microhardness, which could suggests better resistance against the wear and grindability.