Wyniki wyszukiwania - BazTech

1

Badania odporności na pękanie kompozytów ziarnistych na osnowie tlenku glinu przeznaczonych na ostrza narzędzi skrawających

Szutkowska M, Smuk B, Boniecki M

Mechanik

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2012

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R. 85, nr 7

569--573

2

The selection of phase composition of silicon nitride ceramics for shaping with the use of EDM machining

Putyra P., Laszkiewicz-Łukasik J., Wyżga P., Podsiadło M., Smuk B.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 48, nr 1

35--40

EN

Purpose: The purpose of this study is the selection of phase composition of Si3N4 matrix ceramics with the addition of conducting phases so as to make shaping of those materials possible by means of electro discharge machining (EDM). Silicon nitride matrix materials with the addition of oxide phases (Al2O3, MgO, ZrO2) and conducting phases (TiB2, TiN) were sintered by the method of SPS (Spark Plasma Sintering). Additionally the effect of oxide phases on silicon nitride sintering capacity, the value of electric resistance of nitride ceramics depending on the addition of a conducting phase and the effect of sintering parameters on selected features of produced materials were determined. Design/methodology/approach: Materials were sintered with the use of a SPS device marked with FCT-HP D 5. Apparent density Pp was measured by the hydrostatic method. Hardness was determined by the Vicker’s method at the load of 980.7 mN with the use of a Future Tech Corp digital hardness tester FM7. For the purpose of those tests a surface was prepared with the use of a Struers cutting grinder ACUTOM. Measurements of Young’s modulus for sintered samples were carried out using a ultrasonic method of transverse and longitudinal wave speed measurement with the use of a Panametrics Epoch III detector. Resistance measurement was done with the use of Wheatstone and Thomson technical bridges. Findings: The addition of titanium nitride had no effect on the reduction of electric resistance of Si3N4 matrix ceramics. The lack of electric conductivity of those materials is the result of used additions influencing sintering capacity, mainly magnesium oxide. Si3N4 matrix materials with the addition of titanium diboride are characterised by low electrical resistance with high physical and mechanical features maintained. Electric conductivity of those materials and the initial electro discharge cutting attempts prove that it is possible to shape Si3N4 matrix ceramic materials with the addition of a TiB2 phase with the use of EDM process. Practical implications: The use of EDM will enable the production of elements with complicated shapes (impossible to achieve by other shaping methods) from ceramic materials (with Si3N4 matrix). Originality/value: By the appropriate selection of a conducting phase addition it is possible to increase electric conductivity of silicone nitride matrix ceramics, for which it is possible to shape products by means of electro discharge machining.

3

Selected mechanical properties and microstructure of Al2O3ZrO2nano ceramic composites

Szutkowska M., Smuk B., Kalinka A., Czechowski K., Bućko M., Boniecki M.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 48, nr 1

58--63

EN

Purpose: Basic mechanical properties of the studied tool materials and microstructure of alumina-zirconia ceramic composites with fraction of nanopowders have been presented. Design/methodology/approach: The present study reports selected properties obtained by reinforcing Al2O3 with 15 wt% ZrO2 (partially stabilized with Y2O3-Y5) and, non-stabilized zirconia. Specimens were prepared based on submicro- and nano-scale trade powders. Vickers hardness (HV1), wear resistance and fracture toughness (KIC) at room and elevated temperatures characteristic for tool work were evaluated. Microstructure was observed by means of a scanning electron microscopy (SEM). Preliminary industrial cutting tests in the turning of higher-quality carbon steel C45 grade were carried out. Findings: The addition of nanopowders does not result in a significant improvement in fracture toughness at room temperature. A reduction in fracture toughness of KIC(ET) by approximately 20% is observed at elevated temperature (1073 K) for the specimen only with submicro powders in comparison to that at room temperature. Addition of the powder mixture in submicron and nano scale size reveals the minor reduction of fracture toughness (up to 10%) at elevated temperature. Practical implications: The results show that using of powders in submicron and nano scale size not improve the tool life but influences the fracture toughness et elevated temperatures. Originality/value: The results of the presented investigations allow rational use of existing ceramic tools.

4

Properties of alumina ceramics obtained by conventional and non-conventional methods for sintering ceramics

Figiel P., Rozmus M., Smuk B.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 48, nr 1

29--30

EN

Purpose: The aim of this study was to obtain ceramic alumina materials by using the conventional free sintering process, 2.45 GHz microwave sintering (MW) and spark plasma sintering (SPS). Technical and ultra-pure alumina was used to obtain specimens. The effect of temperature and time of sintering on the density, porosity, Young’s modulus and Vickers hardness of Al2O3 ceramics was determined. Mechanical and physical properties of the obtained materials were compared between the methods of sintering. Design/methodology/approach: Al2O3 ceramics materials were sintered by the conventional free-sintering process and the non-conventional methods comprise microwave sintering and spark plasma sintering. Density, porosity, elastic modulus and Vickers hardness were determined for the obtained materials from technical and ultra-pure alumina. Findings: The use of advanced sintering processes allowed the authors to receive alumina ceramic materials with good mechanical and physical properties at the time of one minute for microwave sintering to ten minutes for spark plasma sintering. According to the theory sintering temperature increases with increasing of alumina purity, which was confirmed in the carried out works on the basis of Young’s modulus values and density values. Practical implications: Alumina ceramics made by the microwave sintering process and spark plasma sintering can be applied as the ceramics for cutting tools and also elements of the pharmaceutical equipment because microwave sintering ensures purity of the sintered materials. Originality/value: The non-conventional methods for sintering ceramics primarily comprises (SPS) and (MW). SPS simultaneously applies pulsed electrical current and pressure directly on the sample leading to densification at relatively lower temperatures and short retention times. In the recent years, MW occurred as an advanced sintering technique in the world. Among many works on sintering alumina and alumina-composites until now there have been no reports of microwave sintering of alumina in Poland. Microwave sintering offers increased density and requires lower sintering temperature and time. Shorter sintering prevents the grain growth process, which provides better microstructure and, thanks to these, better mechanical and physical properties. Keywords: Ultra-pure alumina; Microwave sintering; Spark plasma sintering; Free sintering; Mechanical properties.

5

Alumina-Ti(C,N) ceramics with TiB2 additives

Putyra P., Podsiadło M., Smuk B.

Archives of Materials Science and Engineering

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2011

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Vol. 47, nr 1

27-32

EN

Purpose: The aim of the study presented in this article is to determine the effect of TiB2 addition on the selected properties of ceramic tool materials. The effect of titanium diboride additives on the density, porosity, Young’s modulus and Vickers hardness of Al2O3-Ti(C,N) matrix ceramics was determined. Design/methodology/approach: Al2O3-Ti(C,N) ceramics with TiB2 addition were sintered by SPS method. Materials for SPS sintering were pressed in graphite die with pressure of 35 MPa. The max. pressure was obtained after 10 minutes. Sinter process was operated in nitrogen atmosphere. Density, Vickers hardness and Young’s modulus was determined for these materials. The materials were also subjected to tribological analysis. The results were compared with the properties of Al2O3-Ti(C,N) matrix material. Findings: The use of SPS-method in the production of ceramic materials is possible reduce sintering temperature and sintering time. Depending on the TiB2 additives used, the relative density values of individual materials were in the range of 94.4% to 97.7%. Young’s modulus values for these materials were in the range of 392 GPa to 414 GPa, and Vickers hardness in the range of 1966 to 2225 HV1. The results of tribological analysis showed a friction coefficient value for the matrix material of 0.51. For the other materials, the friction coefficient values were in the range 0.31 to 0.49. Practical implications: Ceramic materials with the addition of titanium diboride may be used in cutting tools. Study of the composition and production technology of such tools allows for the minimisation of the use of liquid cooling lubricants in the machining process and the achievement of higher cutting speeds. Originality/value: Titanium diboride additives were added to the structure, resulting in a reduced coefficient of friction, which was measured at between 61% and 96% of the base material coefficient.

6

Ceramiczne tworzywa narzędziowe z udziałem faz nanometrycznych

Jaworska L., Szutkowska M., Smuk B., Klimczyk P., Królicka B.

Mechanik

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2010

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R. 83, nr 4

275-279

PL

Na podstawie wyników badań własnych przeprowadzono analizę zjawisk i zagrożeń dotyczących spiekania ceramicznych nanoproszków. Przedstawiono wyniki spiekania swobodnego i wysokociśnieniowego trzech tworzyw kompozytowych z udziałem nanoproszków. Zaprezentowano trzy grupy materiałów: o osnowie Si3N4, Al203 oraz o osnowie diamentu.

EN

Analysis of the phenomena and hazards related to the process of sintering ceramic nano powders and ceramic materials containing nano powders were carried out with reference to the home investigation. Presented are the alternative free and high pressure sintering operations on composites containing nano powders. These materials were split into three groups: material one with Si3N4 matrix, material two with Al203 matrix and material three with diamond matrix.

7

Analysis of residual stresses using the sin2Ψ method for Al2O3 materials before and after grinding and heat treatment processes

Putyra P., Skrzypek S., Smuk B., Podsiadło M.

Materiały Ceramiczne

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2010

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T. 62, nr 3

301-306

EN

This work presents the results of analysis of residual stresses generated at various stages of production of Al2O3 sinters (sintering, mechanical processing). Residual stresses were determined by the g-sin2Ψ X-ray method. The process of ceramic sintering of Al2O3 was carried out at varying parameters: temperature and heating time, heating rate, cooling rate. After mechanical processing (grinding), the materials were subjected to heat treatment, consisting of heating to temperatures in the range of 600 - 1200 °. In order to determine the mechanical properties of the materials, HV30, HV0.3 and HV0.1 hardness measurements were made. K(Ic) and HVG stress intensity index values were also determined.

PL

W pracy zaprezentowano wyniki analizy naprężeń resztkowych powstających na różnych etapach produkcji spieków Al2O3 (spiekanie, obróbka mechaniczna). Naprężenia resztkowe oznaczono rentgenowską metodą g-sin2Ψ. Spiekanie ceramiki Al2O3 przeprowadzono przy zróżnicowanych parametrach procesu - temperatura i czas ogrzewania, szybkość ogrzewania i studzenia. Po obróbce mechanicznej (szlifowanie) materiały poddano obróbce cieplnej polegającej na ogrzewaniu do temperatury z zakresu 600 - 1200 stopni C. Aby określić właściwości mechaniczne zmierzono twardość HV30, HV0.3 i HV0.1 materiałów. Oznaczono też wartości współczynników intensywności naprężeń K(Ic) i HVG.

8

Alumina composites with solid lubricant content

Putyra P., Podsiadło M., Smuk B.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 41, nr 1-2

34-39

EN

Purpose: The aim of the study presented in this article is to determine the effect of the addition of solid lubricating substances on the selected properties of ceramic tool materials. The effect of tested lubricant additives on the density, porosity, Young’s modulus and Vickers hardness of Al2O3-based ceramics with Ti(C,N) was determined. Design/methodology/approach: Ceramic materials based on aluminium oxide with the addition of solid lubricating substances. Materials were obtained by uniaxial compression with the addition of sliding substances, then isostatically pressed, and dried. The sintering process was carried out at a temperature of 1750°C under high vacuum conditions. Density, Vickers hardness and Young’s modulus was determined for these materials. The materials were also subjected to tribological analysis. The results obtained were compared with the properties of ceramic material based on Al2O3 + 30 mass.% Ti(C,N), from which tool materials were made. Findings: The use of solid lubricating substances in the production of ceramic materials allowed a reduction in the coefficient of friction. Depending on the sliding additives used, the relative density values of individual materials were in the range of 85.3% to 92.3%. Young’s modulus values for these materials were in the range of 273 GPa to 343 GPa, and Vickers hardness in the range of 966 to 1373 HV1. The results of tribological analysis showed a coefficient of friction value for the base material of 0.51. For the other materials, the coefficient of friction values were in the range 0.28 to 0.41, the lowest value being for the material with the addition of BaZrO3. Practical implications: Ceramic materials with the addition of solid lubricating substances may be used in cutting tools. Study of the composition and production technology of such tools allows for the minimisation of the use of liquid cooling lubricants in the machining process and the achievement of higher cutting speeds. Originality/value: Ceramic materials intended for cutting tool blades were produced with the addition of materials of a layered structure or of high cleavage by free sintering. These materials were added to the structure, resulting in a reduced coefficient of friction, which was measured at between 55% and 75% of the coefficient of friction of the base material. The coefficient of friction was determined for friction pairs: ceramic material - high hardness steel ball.

9

The analysis of strength properties of ceramic preforms for infiltration process

Putyra P., Kurtyka P., Jaworska L., Podsiadło M., Smuk B.

Archives of Materials Science and Engineering

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2008

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Vol. 33, nr 2

97-100

EN

Purpose: The goal of this work is the optimization of sintering process of the ceramic preforms based on Si3N4 and Al2O3-Ti(C,N) materials. The influence of pore forming additives on porosity, microstructures and compressive strength are investigated. The aim of this study is to obtain the nitrides and carbides base preforms material for the infiltration process of molten aluminium alloys. Design/methodology/approach: The method of obtaining the silicon nitride and oxide-carbonitride porous preform for the infitration process is the free sintering process. The preforms were produced by the mixing of ceramic powders with organic binders, drying and sintering. Porosity, density were measured for the materials. Microstructure observation was carried out using scanning microscope. The compressive strength of Si3N4 and Al2O3-Ti(C,N) porous preforms were investigated. Findings: For sintered porous Si3N4 preforms, influence of the porous forming additives on material porosity is observed. Compressive strengths of Si3N4 were in the range of 2.9-4.8 MPa. The highest value of the compressive strength was obtained for Al2O3-Ti(C,N) preform with 8 wt.% of tylose and 25 wt.% of glykol. For these materials compressive strength were in the range of 13.2 up to 14.3 MPa. In spite of lower value of the compressive strength for Si3N4 preforms, this material exhibits high shock thermal resistance. Practical implications: Pressureless infiltration of molten metals into ceramics is the most cost-effective approach to liquid-metal processing of MMCs. Metal matrix composites are applied widely in aircraft production technologies and defence technology. Originality/value: Infiltration of molten metals into porous ceramic preforms is the only technique suitable for the fabrication of high volume fraction of ceramic materials in MMCs. Infiltration process generates thermal stresses in the ceramics preforms. The thermal shock resistance of Al2O3 is lower than Si3N4 or Al2O3-Ti(C,N) materials. New kinds of porous materials were obtained.

10

Nitride and carbide preforms for infiltration process

Sobczak N., Jaworska L., Podsiadło M., Smuk B., Nowak R., Kurtyka P., Twardowska A.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 11

653-656

EN

Purpose: Infiltration of molten metals into porous ceramic preforms is the only technique suitable for the fabrication of high volume fraction of ceramic materials in MMCs. The most popular material for porous preforms is Al2O3 because of its low cost. Infiltration process generates thermal stresses in the Al2O3 preforms. The thermal shock resistance of Al2O3 is lower than for Si3N4 or Al2O3/TiC+TiN materials. The aim of this study is to obtain the nitride and carbide base preforms material for the infiltration process of molten aluminium alloys. Design/methodology/approach: The method of obtaining the silicon nitride and oxide-carbonitride porous preform for the infiltration process is the free sintering process. Some of selected properties of this material are presented. The preforms were produced by the mixing of ceramic powders with organic binders, followed by forming, drying and firing. Ceramic preforms of 65% porosity were produced. Microscopic investigations revealed good joints between the ceramic particles. Findings: The material consist of the base component (90 wt.% of α-Si3N4, 5 wt.% of Al2O3, 5 wt.% of Y2O3), which were mixed with 40 wt.% of polyethylene glycol 6000 (mixed in Turbula) porosity is 25.7 %. The higher value of porosity 66.6% was obtained for material with 20 wt.% tylose. The grain size of Si3N4 and method of the mixtures preparing (mixing with or without milling) have the significant influence on compacts' porosity. For 68 wt.% Al2O3, 2 wt.% ZrO2 and 30 wt.% Ti(C,N) with addition of glycol 6000, the value of porosity is 67%.-Si3N4 material produced shows strong bonding with aluminium and AlSi11 aluminium alloy. Practical implications: Pressureless infiltration of molten metals into ceramics is the most cost-effective approach to liquid-metal processing of MMCs. Metal matrix composites are applied widely in aircraft production technologies and defence technology. Originality/value: Compared to widely used alumina performs, those made from non-oxide ceramics demonstrate better physicochemical compatibility with aluminium alloys. New kinds of porous materials were obtained.

11

Obróbka wybranych materiałów trudnoobrabialnych za pomocą płytek skrawających ceramicznych, w tym powlekanych warstwami PVD

Czechowski K., Wszołek J., Kasina J., Pofelska-Filip I., Smuk B., Kurleto A.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2006

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z. 66 [227]

59-67

PL

Na podstawie wyników badań przeprowadzonych w Instytucie Zaawansowanych Technologii Wytwarzania przedstawiono możliwości stosowania do obróbki wybranych materiałów trudnoobrabialnych płytek skrawających ceramicznych, w tym powlekanych warstwami PVD. Omówiono ekologiczne, ekonomiczne i technologiczne aspekty ww. obróbki, ze szczególnym uwzględnieniem wymaganej jej dokładności i trwałości ostrzy. Wyniki uzyskane w Instytucie odniesiono do danych z innych ośrodków badawczych krajowych i zagranicznych. W podsumowaniu przedstawiono wnioski poznawcze i utylitarne.

EN

Basing on the results of research work carried out in the Institute of Advanced Manufacturing Technology, the possibilities of applications of uncoated and PVD coated ceramic cutting inserts to the machining of the selected hard to machine materials are presented. Ecological, economic and technological aspects of the above mentioned machining are discussed with special regards to the required accuracy of machining and tool lives of cutting edges. The results obtained in the Institute are compared to the data received at other national and international institutions. The conclusions of cognitive and utility character are presented in the summary.

12

Tworzywa cermetalowe przeznaczone na ostrza narzędzi skrawających

Jaworska L., Smuk B., Królicka D., Wszołek J.

Kompozyty

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2005

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R. 5, nr 3

21-25

PL

Z uwagi na plastyczność i twardość cermetale można umieścić pomiędzy węglikami spiekanymi a ceramiką skrawającą. Dzięki małemu powinowactwu do stali i odporności na utlenianie w podwyższonych temperaturach cermetale wykazują znacznie lepsze własności skrawne oraz znakomitą odporność na zużycie adhezyjne i dyfuzyjne w porównaniu z węglikami spiekanymi. Jako podstawowe składniki spiekanych cermetali wybrano: TiC, Ti(CN), Mo2C oraz Ni i Mo. Wstępne próby spiekania prowadzono dla mieszanek z Ti(CN) w atmosferze azotu, argonu i w próżni, natomiast dla mieszanek z TiC zastosowano atmosferę argonu i próżnie. W wyniku przeprowadzonych badań wstępnych wybrano następujący skład materiału: 55% masy TiC oraz mieszaninę proszków Ni i Mo. Uzyskano materiał praktycznie bezporowaty, o twardości HV1 18,2 GPa. Badania użytkowe płytek wykonanych z materiału z TiC potwierdzają możliwość zastosowania tego materiału do celów skrawania. Przedstawiono wyniki wstępnych prób otrzymania materiału o strukturze gradientowej. Materiał gradientowy zapewnia narzędziu skrawającemu twardą, odporną na zużycie ścierne warstwę powierzchniową i mniej kruchy, wytrzymały korpus. Zastosowanie materiałów gradientowych jest korzystne także ze względów ekonomicznych oraz ułatwia połączenie płytek z cermetalu z korpusem narzędzi drogą lutowania. Materiały gradientowe zagęszczano dwoma sposobami: metodą sedymentacyjną oraz metodą warstwowego zasypywania mieszanek proszków o zróżnicowanym składzie fazowym. Przedstawiono analizę makro- i mikrostruktury otrzymanych cermetali oraz zmiany twardości wzdłuż przekroju tych materiałów.

EN

Cermetals have very good plasticity and high hardness. Properties of these materials are placed between carbides and cutting ceramics. Due to their low chemical affinity to steel and the resistance for high temperatures oxidation of cermetals have better cutting properties than carbides. Application of cermet inserts guarantees the high quality of machining surface (low roughness). Cermets could be used in ,,dry cutting" process. Materials were sintered at Nz, Arj and vacuum atmospheres at various temperatures. For these researches were used: TiC, TiCN, Mo2C (Tables 1, 2). These materials have low porosity of about 0.05% (Fig. 2). Material with 55 wt.% of TiC and 45 wt.% of (Ni+Mo) has hardness of HV1 18.2 GPa (Tab. 3). Material is characterized by high wear resistance similar to Al2O3 compacts, which was measured on the special IOS apparatus. Cutting inserts were prepared using these cermetals. Wear land width VBB, cutting time, tools live are tested. The 45 steel was machining. Wear land of this inserts VBg = 30 was reached after 12 min (Tab. 4). TiC grains have significant influence on the tutting process. In the future works the finer grains of TiC powders are needed. In this moment material has properties predisposition for cutting tool applications. The functionally graded materials (FGM) were prepared by the layers pressing method (Fig. 1) and the sedimentation method. Functionally graded cermetals have more amount of hard phase in the surface layer and lower participation of this phase in the body frame. FGM secure obtaining of tools (inserts) with hard wear resistance surface layer and the ductile body frame. The gradient of hardness measurement is presented in Figure 4. The functionally graded materials have high porosity. It is a result of various content and conditions of sintering for its layers.

13

Effect of nitride nano-scale multilayer coatings on functional properties of composite ceramic cutting inserts

Czechowski K., Pofelska-Filip I., Królicka B., Szlosek P., Smuk B., Wszołek J., Kurleto A., Kasina J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2005

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Vol. 53, nr 4

425-431

EN

A short literature survey which justifies coating of ceramic cutting inserts is presented. The results reported are on se1eeted nitride coatings, in particular nanoscale multilayer, with layers of type Ti-Zr-N, TiN, ZrN and (TiAl)N, deposited by the are PVD method on oxidecarbide ceramic cutting inserts of type TACN and TW2 produced at the Institute of Advanced Manufacturing Technology. Measurements and quality assessments were made, including of thickness of the coatings and of their constituent micro and nanolayers, microhardness of the coating and of the substrate, surface roughness of the inserts and of the cylindrical workpices turned with these tools. Lifetimes of the coated and uncoated inserts were compared in turning an alloy tool steel. A significant increase in lifetime of the coated TW2 cutting tools was shown.

14

Nowy gatunek ceramiki mieszanej TACN.

Wszołek J., Kasina J., Smuk B.

Mechanik

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2004

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R. 77, nr 5-6

372-373

15

Kierunki rozwoju obróbki skrawaniem i ceramicznych materiałów narzędziowych

Jaworska L., Smuk B.

Materiały Ceramiczne

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2003

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R. 55, nr 4

137-143

PL

W artykule przedstawiono najważniejsze kierunki rozwoju obróbki skrawaniem, głównie w zakresie obróbki szybkościowej, wysokowydajnej i bez cieczy chłodzących. Zestawiono najważniejsze właściwości ceramicznych materiałów skrawających Al2O3,Si3N4, SiAlONu i materiałów supertwardych. Wskazano na możliwość modyfikacji właściwości tych materiałów między innymi poprzez wprowadzenie wiskerów SiC, zastosowanie ciśnień oraz nanoproszków w procesie spiekania.

EN

The paper presents the most important achievements and trends in the field of the machining: high speed cutting, high performance and dry cutting. Main properties of ceramic tool materials: Al2O3, Si3N4, SiAlON and superhard materials were characterized. Some methods of the properties modification for these materials were presented. For example the influence of the SiC whiskers addition, the nanopowders sintering and sintering under pressure conditions on increasing of mechanical properties was showed.