Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: difficult-to-machine materials

Sortuj według:

Ogranicz wyniki do:

Development of a new high-pressure cooling system for machining of difficulut-to-machine materials

100%

Tanabe I. , Yamagami Y. , Hoshino H.

tom Vol. 20, No. 1

82--97

In recent years, titanium alloys and nickel alloys have become eminent for making aeronautic and astronautic parts. Since both nickel and titanium alloys have a very small thermal conductivity, the being used tool will suffer from huge damage by heat generated during the grinding process. Therefore, there is a requirement for a durable tool with excellent cooling capacity. In this research, the technology regarding the new forced cooling using with high-pressure coolant for machining difficult-to-machine material was developed and evaluated. A through-hole in the near the tip on the rake face of the turning tool is firstly machined by electrical discharge machining. High-pressure coolant was then supplied to the turning tool from the hole on the bottom of the tool. Several values of pressure were tried in many experiments. It is concluded from the results that; (1) a new forced cooling method in the form of drilling a hole at the tip of the tool from which supply high-pressure coolant, a tool temperature decrease and a tool-life prolongation could be achieved, (2) the technology could effectively cool near the tip of turning tool, (3) the chip was effectively broken by the high pressure, (4) It was confirmed that the tool cutting edge condition was stabilized, the surface roughness of the machined workpieces was improved, the tool hardness was maintained and the tool-life was prolonged due to the cooling effect of the devised tool.

Precyzyjne cięcie laserem tlenku cyrkonu IV (ZrO2)

63%

Nowak A. , Wyszyński D.

tom Vol. 20, nr 2

13--19

Precision laser machining of a difficult to machine materials is a complex issue and requires the involvement of the wide knowledge and experience in the field of science materials and physical phenomena occurring in the within the interaction site of the laser beam with the material workpiece. Correct selection of the laser source and equipment system with appropriate instrumentation allows the processing of materials in an efficient and cost-effective way and also allows to fulfill the requirements for treatment of the materials on a micro scale. From the analysis of the results it can be concluded that the edges resulting from laser treatment carried grooves are sharp (samples 9, 10, 11), which predisposes the type of processing to perform the blades of the cutting tools. Depth obtained in these tests grooves (single-pass laser beam) may indicate a high performance cutting process of cutting teeth. In view of the aforementioned facts, it is expected to shorten the preparation time of the cutting blade, thereby reducing production costs. As a result, it is possible to increase the competitiveness of companies doing good quality tools made lower than the standard cost-effectively, and thus this type of solution has the potential of development for native Polish enterprises, so that they offer can become complementary to the tycoons on the Polish market aspect of the production of custom, dedicated ie. “tailor-made” tools. Based on the study it can be concluded that the use of DPSS Nd: YAG laser (λ = 532 nm), with appropriate selection of process parameters for precise and efficient laser shaping of difficult to cut materials, such as described in the work - zirconium dioxide. Further studies will aim to establish guidelines for the planning process precision laser cutting of other materials from the group of difficult ones, such as PCD, diamond, Al.2O3 (sapphire) or c-BN. This is particularly important from the point of view of the precise shape of cutting tools used widely in the aerospace, automotive and carpentry.

Hybrydowe procesy skrawania wspomagane mediami technologicznymi

51%

Grzesik W.

tom R. 91, nr 12

1050--1056

Przedstawiono hybrydowe sposoby skrawania, wykorzystujące wspomaganie mediami technologicznymi (media-assisted machining – MAM). Omówiono zasady i możliwości technologiczne intensywnego chłodzenia CCS pod dużym ciśnieniem (high pressure cutting – HPC), minimalnego chłodzenia (minimum quantity cooling/lubrication – MQC/MQL), chłodzenia kriogenicznego (cryogenic machining – CM) oraz integracji tych oddziaływań w procesie skrawania w różnych zastosowaniach przemysłowych – zwłaszcza w przypadku kształtowania elementów z materiałów trudnoskrawalnych. Opisano sposoby zasilania mediami technologicznymi oraz rozwiązania narzędzi/systemów narzędziowych i wyposażenie obrabiarek hybrydowych CNC. Podano przykład optymalizacji obróbki MAM z uwzględnieniem chłodzenia kriogenicznego.

A special group of hybrid assisted processes termed media-assisted processes which various liquid and gaseous media supplied to the cutting zone is highlighted. Special attention is paid on such cooling techniques as high-pressure machining (HPC), high-pressure jet assisted machining (HPJAM), minimum quantity cooling/lubrication (MQC/MQL) and a group of cryogenically cooled machining including such cryogenic media as CO2 snow and liquid nitrogen (LN2). Some important effects resulting from the various cooling strategies are outlined and compared. In particular, quantitative effects concerning chip breaking, thermal and tribological behavior of the cutting process as well as burr reduction, surface quality and subsurface layer are presented. The optimization procedure concerning both energy consumption and machining costs in terms of material removal rate (MRR) is presented.