Wyniki wyszukiwania - Biblioteka Nauki

1

Study on steel matrix composites with (Ti,Al)N gradient PVD coatings

100%

Matula G.

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tom Vol. 34, nr 1

79-86

EN

Purpose: The paper presents investigation results of structure and properties of steel matrix composites (SMC) uncoated and coated with hard (Ti,Al)N gradient coatings with use of physical vapour deposition process. Design/methodology/approach: Powder Metallurgy, PVD, TEM, SEM, XRD, GDOES, Microhardness tests, Scratch test. Findings: Depositing of gradient (Ti,Al)N coatings onto SMC materials meets the requirements connected with hybrid technology of production, joining powder metallurgy and physical vapour deposition techniques, in area of producing modern composite gradient tool materials. Sintered steel matrix composites reinforced with hard carbide phases and deposited with gradient PVD coatings can be widely employed in industry for tools, especially for machining and plastic forming processes. Practical implications: Tool materials used especially for tools employed especially in machining and plastic forming processes. Originality/value: Modern methods of powders’ forming application make possible to achieve gradient structure of tool, which is very advantageous in respect of mechanical properties. Employed compositions of technologies joining powder metallurgy and physical vapour deposition techniques give the possibility to achieve high properties characteristic of cemented carbides with the high ductility characteristic of steels.

2

Application of Ceramic Injection Moulding and Pressure Infiltration to the Manufacturing of Alumina/AlSi10Mg Composites

100%

Matula G.

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nr 4

3

Wpływ obróbki cieplnej na strukturę i własności stali szybkotnących wytworzonych metodą PIM

63%

Dobrzański L. A. , Matula G.

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tom R. XXIV, nr 6

279-282

PL

Na podstawie przeprowadzonych badań stali szybkotnących formowanych z gęstwy polimerowo-proszkowej (PIM) i porównaniu ich do wyników badań stali prasowanych i spiekanych (PM), prasowanych izostatycznie na gorąco (HIP) oraz konwencjonalnych stwierdzono, że strukturę wszystkich badanych stali szybkotnących w stanie zahartowanym, stanowi martenzyt, austenit szczątkowy oraz węgliki pierwotne typu MC i M6C częściowo rozpuszczone w roztworze stałym podczas austenityzowania. Wyższe stężenie węgla powoduje zwiększenie udziału austenitu szczątkowego w stalach (PIM) i niższą twardość po hartowaniu w stosunku do tych samych gatunków wytwarzanych innymi metodami. Wysoki udział austenitu szczątkowego po hartowaniu spada dopiero po odpuszczaniu w temperaturze 600 stopni Celsjusza do wartości 10% dla stali HS6-5-2 PIM oraz 8% dla stali HS12-1-5-5 PIM i powoduje wzrost twardości po odpuszczaniu w tej temperaturze do wartości maksymalnych, wynoszących odpowiednio 63,2 HRC dla stali HS6-5-2 hartowanej z temperatury 1180 stopni Celsjusza i odpuszczonej w 600 stopni Celsjusza oraz 67,6 HRC dla stali HS12-1-5-5 hartowanej z temperatury 1210 stopni Celsjusza i odpuszczonej w 600 stopni Celsjusza. Przeprowadzone badania trybologiczne wykazują, że stale doświadczalne cechują się wysoką odpornością na zużycie ścierne w porównaniu do stali wytwarzanych innymi metodami.

EN

On the basis of investigations of high-speed steels formed out of polymer-powder slurry (PIM) and their comparison with results of investigations of pressed and sintered steels (PM), hot isostatic pressed (HIP) and conventional it has been shown that the structure of all examined high-speed steels in quenched state is martensite, retained austenite and primary carbide MC and M6C types partially dissolve in solid solution during austenitizing. Higher carbon concentration causes increase of the retained austenite portion in those (PIM) steels and lower hardness after quenching in relation to the same grades manufactured by the other method. A high retained austenite portion after quenching falls after tempering at the temperature of 600 degrees centigrade to the value 10% for HS6-5-2 PIM steel and 8% for HS12-1-5-5 PIM steel results in hardness increase after tempering at this temperature to the maximum values equalled 63,2 HRC for HS6-5-2 steel quenched from temperature of 1180 degrees centigrade, and tempered at 600 degrees centigrade and hadness 67,6 HRC for HS12-1-5-5 steel quenched from temperature of 1210 degrees centigrade and tempered at 600 degrees centigrade, respectively. Outcarried tribological investigations have shown that experimental steels are characterised by high abrasive wear with comparison with steels manufactured in the other methods.

4

Influence of binder composition on the properties of feedstock for cemented carbides

51%

Gołombek K. , Matula G. , Mikuła J. , Dobrzański L.

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2011

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tom Vol. 51, nr 2

116-124

EN

Purpose: The plastic mixtures shaping of polymer-powder slurries with use of injection moulding and extrusion techniques for development and optimization of metal matrix tool materials reinforced with hard carbide phases. Design/methodology/approach: Mixtures preparation and preliminary tests, injection moulding and extrusion moulding processes optimization, the grain size measurement with use of laser diffraction method, torque measurement, rheological characterization, differential scanning calorimetry. Findings: All of investigated polymer-powder mixtures are proper for injection moulding and extrusion processes. Increasing the maximal possible fraction of carbides powder in the mixture is possible due to SA acid addition in the composition of binder. Advantages of SA acid as a component of binder are connected with significant decreasing the viscosity of polymer-powder mixtures as a result of SA acid presence. Binder fraction in injection moulded and extruded materials should be as small as possible, but enough for slurry moulding process. Too large fraction of binder causes the problems during degradation process because of higher shrinkage value and can be a reason of the distortion effect during sintering process. The results of bending strength measurements of injection moulded and extruded samples depends mainly on the moulding conditions, which should be optimized, to obtain the homogeneous structure of material with no discontinuities. Practical implications: Using investigated PM methods makes it possible to take advantage of injection moulding benefits obtained in area of polymer materials to fabrication of metallic materials, cermets and ceramics. There are wide possibilities of PIM (Powder Injection Moulding) method application for “near-net-shape” production of small size units with complicated shape and extended surface so the range of practical use of this method is wide and covers many aspects of life. The elimination the plastic forming and machining operations causes the significant economic and ecological benefits. Originality/value: It is expected, that the further research on developing an optimal degradation and sintering conditions may enable achieving the ready to use tool materials based on cemented carbides with the properties exceeding the classical PM processes results.

5

Application of Ceramic Injection Moulding and Pressure Infiltration to the Manufacturing of Alumina/AlSi10Mg Composites

51%

Matula G. , Krzysteczko-Witek J. , Tomiczek B.

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tom Vol. 63, iss. 4

2101--2106

EN

Ceramic injection moulding and gas pressure infiltration were employed for the manufacturing of alumina/AlSi10Mg composites. Porous ceramic preforms were prepared by mixing alumina powder with a multi-binder system and injection moulding of the powder polymer slurry. Then, the organic part was removed through a combination of solvent and thermal debinding, and the materials were finally sintered at different temperatures. The ceramic preforms manufactured in this way were infiltrated by an AlSi10Mg alloy. The microstructure and properties of the manufactured materials were examined using scanning electron microscopy, mercury porosimetry and bending strength testing. The results of transmission electron microscopy and scanning electron microscopy observations show that the fabricated composite materials are characterised by the percolation type of the microstructure and a lack of unfilled pores with good cohesion at the metal-ceramic interfaces. This is surprising considering that over 30% of the pores are smaller than 1 μm. The results show that the bending strength of the obtained composites decreased with increasing sintering temperature of the porous preforms.

6

Application of powder injection moulding for manufacturing of tool composite materials

51%

Matula G. , Jędrzejewska-Anioł A. , Niespodziański J.

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2013

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tom Vol. 59, nr 2

80--85

EN

Purpose: The goal of this work is development of the tool composites on the basis of T15 HSS contained 10% of carbides. This tool material were manufactured by Powder Injection Moulding method and sintered. Design/methodology/approach: Torque-load test, rheological tests, thermal debinding, sintering, hardness test and microstructure examinations. Findings: Examination of the effect of the binder type and portion on structure and properties of the experimental tool materials revealed that using the stearic acid for covering the carbides surface reduces viscosity, thus improving technological properties of the feedstock. Employment of polypropylene instead of the high density polyethylene reduces viscosity and torque-load of the investigated feedstocks. Therefore, there is a possibility to increase the portion of the metallic and ceramic powder. Practical implications: Stearic acid significantly reduces the viscosity of tested polymer-powder mixtures, so its use is justified. The share of the binder in materials, injection molded or extruded should be minimal and allows only the formation of the slurry. Too high proportion of binder creates difficulties during the degradation and causes greater shrinkage and possibility of a distortion during sintering. Employment of polyethylene instead of the high density polypropylene reduces viscosity and torque-load of the investigated feedstocks. Therefore, there is a possibility to increase the portion of the metallic or ceramic powder. This results in a lower deformation probability and in a lower sinter shrinkage. Originality/value: In the paper the using extruding of the polymer-powder mix gives the possibility to fabricate cermets which, with their structure and mechanical properties, fill the gap in tool materials between the high-speed steels and cemented carbides.

7

Characterization of Nanometric-Sized Carbides Formed During Tempering of Carbide-Steel Cermets

51%

Pawlyta M. , Matula G. , Gołombek K. , Matus K.

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nr 2

8

Application of powder injection moulding and extrusion process to manufacturing of Ni-YSZ anodes

51%

Matula G. , Jardiel T. , Levenfeld B. , Várez A.

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tom Vol. 36, nr 1

87-94

EN

Purpose: Investigation of the Ni-YSZ cermets for anode supported solid oxide fuel cells (SOFC) prepared by extrusion or powder injection moulding process, sintered and reduced of NiO-YSZ. Design/methodology/approach: Density examination, shrinkage examination, transverse rupture strength tests, microstructure examination. Findings: Results of the rheological and torque investigations have essential importance for further search of the optimum feedstock to injection moulding machines and extruders making forming possible of shapes for fuel cells anodes, which require in addition debinding of the binder, sintering, and reduction. Practical implications: The proposed technological solutions for fabricating anodes as tubes or flat shapes will make connecting the cells into packets possible which will allow increasing the cell power. Originality/value: The presented investigation results confirm purposefulness of employing injection moulding or extrusion for fabrication of fuel cells anodes. These two methods are used for manufacturing elements of devices in a mass scale. Significant interest in fuel cells and rapid development of their production which should take place in the close future may be the reason for searching the inexpensive technological solutions in the manufacturing process of the cells.

9

Simulation of powder injection moulding conditions using cadmould program

51%

Matula G. , Dobrzański L. A. , Ambroziak M.

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2012

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tom Vol. 55, nr 2

556--560

EN

Purpose: Development of a new generation tool materials on the basis of high speed-steel manufactured by Powder Injection Moulding. To investigate formability of the polymer-powder slurry in which the HS12-1-5-5 (T15) high-speed steel powder was used, as well as the HD-PE polyethylene and paraffin, the „Cadmould” commercial software was employed, developed mostly for simulation of the powder injection moulding of the thermoplastic and composites. Design/methodology/approach: Powder metallurgy, powder injection moulding, sintering, microstructure examination, symulation of injection moulding. Findings: Simulation of powder injection moulding was preceded by the rheological tests, which made obtaining possible of the data indispensable for modelling, pertaining to the polymer-powder slurry viscosity. The portion of particles reinforcing the composite is usually lower than powder portion in mixtures used for forming and next binding agent degradation and sintering. The big powder portion is often the reason for the high viscosity of the mixture and problems with its forming. However, simulation results revealed that the fabricated polymer-powder mixture may be injected, which was confirmed by carrying out powder injection moulding on a typical Arburg injection moulding machine using in the industry. Practical implications: Application of powder injection moulding to manufacturing of high speed steel matrix composites gives the possibility to obtain tool materials with the relative high ductility characteristic of steel and high hardness and wear resistance typical for cemented carbides. Originality/value: Application of symulation of powder injection moulding conditions using cadmould program gives the possibility to reduce cost of expensive injection mould and control the injection conditions.

10

Wpływ metody formowania na strukturę i własności materiałów gradientowych

51%

Dobrzański L. A. , Kloc A. , Matula G.

Inżynieria Materiałowa

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2006

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tom Vol. 27, nr 3

584-587

PL

Przeprowadzone badania dotyczą otrzymywania materiału na bazie stali szybkotnącej i stali niestopowej. Do wytwarzania materiałów została zastosowana konwencjonalna metoda metalurgii proszków tj. prasowanie w matrycy zamkniętej, izostatyczne prasowanie na zimno (CIP) oraz nowoczesna metoda formowania niskociśnieniowego proszku. Metody formowania zostały tak zmodyfikowane by otrzymać materiały o strukturze składającej sie z trzech warstw tj. stali niestopowej, stali szybkotnącej i warstwy pośredniej. Badania obejmowały określenie optymalnych warunków spiekania, w szczególności temperatury i cyklu spiekania, jak również wybranych własności mechanicznych. Na podstawie porównania struktury i własności próbek wytwarzanych metodą formowania niskociśnieniowego, metodą CIP lub prasowania w matrycy zamkniętej stwierdzono, że w strukturze wszystkich badanych próbek w stanie spiekanym występują drobne węgliki równomiernie rozmieszczone w osnowie stali szybkotnącej. Zauważono, że niezależnie od metody wytwarzania podwyższenie optymalnej temperatury spiekania powoduje w warstwach złożonych ze stali szybkotnącej niekontrolowany rozrost i koagulacje węglików pierwotnych. Na podstawie badań mikrotwardości stwierdzono, że twardość próbek zarówno formowanych niskociśnieniowo jak i wytwarzanych metodą CIP oraz prasowanych w matrycy zamkniętej i spiekanych wzrasta wraz z temperatura spiekania. Ponadto stwierdzono, że stale formowane niskociśnieniowo cechują sie szerszym zakresem temperatury spiekania.

EN

Investigations carried out referred to obtaining material based on the highspeed steel and non-alloy steel. The conventional powder metallurgy method was used for manufacturing these materials, consisting in compacting the powder in the closed die and sintering it next, the isostatic pressing method (CIP), and the modern pressureless forming powder metallurgy. Forming methods were developed during the investigations for high-speed and non-alloy steel powders, making it possible to obtain materials with three layers in their structure. Investigations included determining the sintering conditions, and especially the temperature and treatment cycle, as well as examining the selected mechanical properties. It was found out, basing on the comparison of structures and properties of test pieces made with the pressureless forming method, as well as with the isostatic pressing and pressing in the closed die, with further sintering, that in structures of all examined test pieces in the sintered state fine carbides occurred distributed homogeneously in the highspeed steel layer. It was noticed, that increase of the sintering temperature, regardless of the manufacturing method, results in the uncontrolled growth and coagulation of the primary carbides and melting up to forming of eutectics in layers consisting of the high-speed steel. It was found out basing on the microhardness tests that hardness of test pieces both those pressureless formed, compacted in the closed die, and isostatically cold pressed and sintered grows along with the sintering temperature. It was also noted that the sintering temperature range is bigger in case of the pressureless formed materials.

11

Analysis of Crystallisation Process of Cast Magnesium Alloys Based on Thermal Derivative Analysis / Analiza Procesu Krystalizacji Odlewniczych Stopów Magnezu W Oparciu O Analizę Termicznoderywacyjną

45%

Król M. , Tański T. , Matula G. , Snopiński P. , Tomiczek A. E.

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nr 4

12

Analysis of Crystallisation Process of Cast Magnesium Alloys Based on Thermal Derivative Analysis

45%

Król M. , Tański T. , Matula G. , Snopiński P. , Tomiczek A. E.

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tom Vol. 60, iss. 4

2993--3000

EN

The paper presents the results of the crystallisation process of cast magnesium alloys based on the thermal-derivation analysis. The effects of aluminium content and cooling rate on the characteristic parameters of the evaluation of magnesium dendrites during solidification at different cooling rates were investigated by thermal-derivative analysis (TDA). Dendrite coherency point (DCP) is defined with a new approach based on the second derivative cooling curve. Solidification behaviour was evaluated via one thermocouple thermal analysis method. Microstructural evaluations were characterised by light microscope, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. This research revealed that utilisation of d2T/dt2 versus the time curve methodology allows for analysis of the dendrite coherency point.

PL

W pracy przedstawiono wyniki badań opisu procesu krystalizacji odlewniczych stopów magnezu w oparciu o analizę termiczno-derywacyjną. Przedstawiono wpływ szybkości chłodzenia oraz stężenia aluminium na charakterystyczne temperatury podczas krystalizacji, jak również wyniki obliczeń udziału frakcji stałej w punkcie koherencji fazy α w oparciu o analizę krzywej d2T/dt2, bazując na pomiarze temperatury jedną termoparą. Przedstawiono i omówiono wyniki wpływu szybkości chłodzenia na charakterystyczne temperatury procesu krystalizacji odlewniczych stopów magnezu. Wpływu założonych szybkości chłodzenia na mikrostrukturę dokonano w oparciu o wyniki badań z wykorzystaniem mikroskopii świetlnej oraz mikroanalizy rentgenowskiej jakościowej i ilościowej z wykorzystaniem elektronowej mikroskopii skaningowej. Przedstawiono wyniki badań składu fazowego w oparciu o rentgenowską jakościową analizę fazową.

13

Effect of carbon concentration on structure and properties of the gradient tool materials

45%

Dobrzański L. A. , Kloc A. , Matula G. , Domagała J. , Torralba J. M.

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tom Vol. 17, nr 1-2

45--48

EN

Purpose: The goal of this project is development of the contemporary gradient materials using the powder metallurgy methods to ensure the required properties and structure of the designed material. Design/methodology/approach: The materials were fabricated with the conventional powder metallurgy method consisting in compacting the powder in the closed die and finally sintering it. Forming methods were developed for the HS6-5-2 high-speed steel and non-alloy steel powders, making it possible to obtain materials with three layers, and later - after their further modification - with six layers in their structure. Findings: It was found out basing on the microhardness tests that hardness of test pieces grows along with the sintering temperature and with carbon content in the interface and non-alloy layers. It was also observed that porosity decreases along with the carbon content in these layers. It was found out, basing on the comparison of structures and properties of the compacted and sintered test pieces, that in structures of all examined test pieces in the sintered state fine carbides occurred distributed homogeneously in the high-speed steel layer. Research limitations/implications: It was noticed, that increase of the sintering temperature results in the uncontrolled growth and coagulation of the primary carbides and melting up to forming of eutectics in layers consisting of the high-speed steel. Practical implications: Material presented in this paper has layers consisting on one side from the non-alloy steel with hardness growing with the increase of carbon content, and on the other side the high-speed steel, characteristic of the high ductility. Such material is tested for turning tools. Originality/value: The layers were poured in such way that the first layers consisted of the non-alloy steel and the last one from the high-speed steel, and were compacted next. The layers inside the material are mixes of the high-speed steel and non-alloy steel powders in the relevant proportions.