Wyniki wyszukiwania - Biblioteka Nauki

1

Materiały na narzędzia do wydajnej wykończeniowej obróbki skrawaniem

100%

Czechowski K. , Stós J. , Wronska I. , Wszolek J.

|

2011

|

tom nr 2

26-28

PL

Obserwowany, zwłaszcza w ostatnim dziesięcioleciu, intensywny rozwój inżynierii materiałowej i wynikające z niego coraz szersze stosowanie nowych gatunków materiałów, szczególnie w przemyśle lotniczym, samochodowym oraz w technice medycznej, stwarza potrzebę dysponowania techniką ekonomicznego kształtowania wysokiej jakości wyrobów wykonywanych z nowych materiałów.

2

Methodology of high-speed steels design using the artificial intelligence tools

84%

Sitek W.

|

2010

|

tom Vol. 39, nr 2

115-160

EN

Purpose: The main goal of the research carried out was developing the design methodology for the new high-speed steels with the required properties, including hardness and fracture toughness, as the main properties guaranteeing the high durability and quality of tools made from them. It was decided that hardness and fracture toughness KIc are the criteria used during the high-speed steels design. Design/methodology/approach: In case of hardness, the statistical and neural network models were developed making computation possible of the high-speed steel hardness based solely on the steel chemical composition and its heat treatment parameters, i.e., austenitizing- and tempering temperatures. In this case results of own work on the effect of alloy elements on the secondary hardness effect were used, as well as data contained in catalogues and pertinent standards regarding the high-speed steels. In the second case - high-speed steels fracture toughness, the neural network model was developed, making it possible to compute the KIc factor based on the steel chemical composition and its heat treatment parameters. The developed material models were used for designing the chemical compositions if the new high-speed steel, demonstrating the desired properties, i.e., hardness and fracture toughness. Methodology was developed to this end, employing the evolutionary algorithms, multicriteria optimisation of the high-speed steels chemical composition. Findings: Results of the research carried out confirmed the assumption that using the data from catalogues and from standards is possible, which - would supplement the set of data indispensable to develop the assumed model - improving in this way its adequacy and versatility. Practical implications: Solutions presented in the work, based on using the adequate material models may feature an interesting alternative in designing of the new materials with the required properties. The practical aspect has to be noted, resulting form the developed models, which may successfully replace the above mentioned technological investigations, consisting in one time selection of the chemical composition and heat treatment parameters and experimental verification of the newly developed materials to check of its properties meet the requirements. Originality/value: The presented approach to new materials design, being the new materials design philosophy, assumes the maximum possible limitation of carrying out the indispensable experiments, to take advantage of the existing experimental knowledge resources in the form of databases and most effective computer science tools, including neural networks and evolutionary algorithms. It should be indicated that the materials science knowledge, pertaining oftentimes to the multi-aspect classic problems and described, or - rather - saved in the existing, broadly speaking, databases, features the invaluable source of information which may be used for discovery of the unknown so far relationships describing the material structure - properties relations.

3

Postępy w konstrukcji narzędzi skrawających

84%

Sałaciński T.

|

2011

|

tom nr 2

5-8

PL

W artykule omówiono postępy i trendy w konstrukcjach współczesnych narzędzi skrawających, dotyczące w szczególności: materiałów narzędziowych, powłok ochronnych, kształtów i mocowania płytek skrawających, mocowania narzędzi oraz narzędzi modułowych, zespołowych, wielozadaniowych i mechatronicznych.

4

Współczesne techniki obróbki skrawaniem kół zębatych. Część II.

84%

Musiałek K. , Pofelska-Filip I. , Fedaczyński A.

|

2006

|

tom R. 79, nr 12

950-950

PL

Materiały narzędziowe i narzędzia skrawające jako uwarunkowania nowych technik obróbki.

5

Structure of sintered gradient tool materials

84%

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

|

2009

|

tom Vol. 32, nr 1

23-28

EN

Purpose: Investigation of influence of sintering conditions onto the structure of composite gradient tool materials. The chemical composition of the investigated materials’ core was corresponding to the M2 high-speed steel and was reinforced with the WC and TiC type hard carbide phases with the growing portions of these phases in the outward direction from the core to the surface. Design/methodology/approach: Powder Metallurgy, SEM, X-Ray Microanalysis. Findings: Changing of technological properties and structure of composite gradient tool materials (depending on the compositions of used mixtures and sintering temperature) was analyzed and described. Practical implications: Tool materials used especially for cutting tools and plastic forming tools. Originality/value: Providing of high properties characteristic of cemented carbides keeping high ductility characteristic of steel was achieved.

6

Miniaturowe wiertła kręte.

84%

Kudła L.

|

1998

|

tom R. LXXI, nr 11

634-636

PL

Budowa ogólna wierteł krętych o średnicach mniejszych od 1 mm. Konstrukcja części skrawającej i geometria ostrzy. Materiały narzędziowe oraz wybrane cechy użytkowe miniaturowych wierteł.

EN

General design of the twist drill with diameter under 1 mm. Basic forms of cutting part and drill bit geometry. Tool materials and some working properties of miniature drills.

7

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

84%

Matula G.

|

2009

|

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.

8

Effect of the sintering parameters on structure of the gradient tool materials

84%

Dobrzański L. A. , Hajduczek J. , Kloc-Ptaszna A.

|

2009

|

tom Vol. 36, nr 1

33-40

EN

Purpose: The purpose of this work was to obtain gradient tool materials, based on the unalloyed steel reinforced with HS6-5-2 high-speed steel, through using the conventional powder metallurgy method and sintering in the vacuum furnace at the range of temperature from 1190°C to 1250°C, in steps of 20°C, for 30 and 60 minutes. Design/methodology/approach: In presented work gradient materials were obtained through powder metallurgy consisting uniaxial compacting method and sintering. The unalloyed steel was fabricated by mixing iron and graphite powders. Structural examinations were carried out by optical microscopy methods assisted with the computer image analysis, scanning electron microscopy and X-ray microanalysis. Findings: It was found out, that increase of the sintering temperature contribute to the undergo coagulation on the grain boundary or creation of the large allocations on the grain boundary of the carbides in the matrix. As well, it was proved, that incompleted sintering process was caused by too low sintering temperature. Practical implications: Such gradient material may be applied for turning tools. Originality/value: A forming methods were developed for unalloyed steel and high-speed steel powders, which made it possible to obtain specimens with six layers in its structure. The material presented in this paper has layers, at one side consisting unalloyed steel and at the other side high-speed steel. The layers inside the material are mixes of the high-speed steel and unalloyed steel powders in the relevant proportions.

9

Skrawalność kompozytów aluminiowo-ceramicznych.

67%

Kawalec M. , Jankowiak M. , Król G.

|

1998

|

tom R. LXXI, nr 2

67-70

PL

Charakterystyka, właściwości i zastosowanie metalowych materiałów kompozytowych (MMC), w tym kompozytów aluminiowo-ceramicznych. Materiały narzędziowe i narzędzia stosowane w obróbce. Skrawalność kompozytów w operacjach toczenia, wiercenia i frezowania przy zastosowaniu na ostrza różnych materiałów narzędziowych.

EN

Characteristic, properties and applications of metallic composite materials (MMC) including aluminium-ceramic composites. Tool materials and tools used in machining. Machinability of composites in turning, drilling and milling with the cutting edge made of different tool materials.

10

Tribological properties of CrNx coatings

67%

Warcholinski B. , Gilewicz A.

|

2009

|

tom Vol. 37, nr 2

498-504

EN

Purpose: The purpose of this work is the characterization of the tribological properties thin Cr-N coatings, both monolayer Cr2N, CrN coatings and multilayer Cr/CrN, Cr2N/CrN coatings, deposited by cathodic arc physical vapour deposition (CAPVD). Design/methodology/approach: The deposition parameters of Cr2N and CrN were determined. Structure of the coatings were investigated using the scanning electron microscopy (SEM). The XRD examination was carried out to specify the phase structure, EDS to define the chemical composition of the coatings. The investigation includes also microhardness, roughness tests, adhesion, friction coefficient and wear rate. Findings: Basing on the scratch test it was shown that the influence of the architecture on the coating’ adhesion is dominant. It was found that the all tested coatings show high critical load Lc2 >70 N. The multilayer coatings show higher critical load when compared to monolayer coatings. Research limitations/implications: The main limitation of this work is linked to the deposition technique itself.It is difficult to avoid surface defects and pinholes that strongly influence the tribological results. Practical implications: Chromium based coatings present good mechanical properties which allow them to be used in several applications; from decorative to protective coatings. Originality/value: The comparison of adhesion and wear resistance of mono- and multilayer coatings based on chromium. The deposition technology enable to obtain the coatings with high adhesion to the substrate. This may be important to advanced coatings industry.

11

Kompozyty Si3N4-TiC modyfikowane tlenkami galu, indu, ceru, cyrkonu i cynku.

51%

Szafran M. , Bobryk E. , Lipiec W. , Olszyna A.

|

2002

|

tom R. XXIII, nr 6

742-745

PL

W pracy przedstawiono wyniki badań nad modyfikacją kompozytów ceramicznych w układzie Si3N4-Al2O3-Y2O3-TiC tlenkami: galu, indu, ceru, cyrkonu i cynku w celu zwiększenia odporności materiału na kruche pękanie. Wartość współczynnika intensywności naprężeń KIC dla wszystkich składów jest bardzo wysoka i waha się od 7,5 do 9 MPa x m do 0,5 w zależności od rodzaju i ilości wprowadzonej domieszki. Największą odpornością na kruche pękanie charakteryzowały się spieki 60% Si3N4-Al2O3-3,5%Y2O3-15% TiC z dodatkiem 11,5% ZrO2 lub 6,5% CeO. Interesujący jest fakt doświadczalny, że wraz ze wzrostem współczynnika KIC nie zmniejsza sie radykalnie twardość spieków. W celu wyjaśnienia przyczyny znaczącego wzrostu odporności na kruche pękanie przeprowadzono badania mikrostruktury spieków.

EN

The paper presents the results of experiments on the modification of ceramic composites of the Si3N4-Al2O3-Y2O3-TiC system by adding gallium, indium, cerium, zirconium or zinc oxides, with the aim of improving the fracture toughness of the material. For all the compositions, the value of the stress intensity factor KIC is very high and ranges from 7.5 to 9 MPa x m to 0,5 depending on the kind and amount of the additive. The best fracture toughness was obtained in 60% Si3N4-Al2O3-3,5%Y2O3-15%TiC sinters added with 11,% of ZrO2 or 6,5% of CeO. An interesting experimental fact is that an increase of the KIC value does not result in any drastic decrease of the material hardness. In order to explain the role played by the additives in increasing so significantly the fracture toughness of the sintered materials, their microstructures were examined.