Wyniki wyszukiwania - BazTech

1

Influence of Water-Jet on Micro-Formed Parts Process via Nano-Indentation and SEM Analysis

Quaisie James Kwasi, Yamba Philip, Mwinteribo Tabie Vitus, Akayeti Anthony, Kukurah Jamal-Deen, Mohammed Abdul-Hamid

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 2

353--361

EN

Based on the experimental study of cavitation water jet impact on microforming, a single round hole micro-die was used in this paper. The effect of different process parameters on the performance of 304 stainless steel foil was examined, which involves the nanometer hardness, and elastic modulus. The nano-indentation tester was used to test the nano-hardness of the formed part, and the performance of the workpiece before and after the impact was analyzed. The nano hardness and elastic modulus increased significantly with an increase in the incident pressure. When the incident pressure was 20 MPa and the impact time of 5 min, the hardness increased by at least 122%, and the elastic modulus increased by at least 76%. After the cavitation water jet shocked the metallic foil of the SEM analysis and the results indicated that, as the incident pressure increases, the surface morphology of the formed part changes from approximately spherical to spherical, and the spherical roundness increases. In addition, there were different degrees of defects at the bottom of the formed part, and as the incident pressure increased, the bottom defects became more and more obvious, from micro-cracks to micro-layer cracks.

2

Experimental assessment of changes in structural steel composition by progressive technology cutting

Mascenik Jozef

Management Systems in Production Engineering

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2021

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nr 4 (29)

266--273

EN

The submitted paper deals with the issue of change in structure, hardness and thermally affected zone of the samples of a toothed wheel part produced by technology of cutting by plasma, laser and water jet. The cutting process by laser and plasma technology causes intensive thermal affection of material and change in structure and microhardness in the cutting area referred to as thermally affected zone. The paper describes three material cutting technologies of the toothed wheel part. The experimental part contains description of experimental sample preparation, its hardness measurement and examination of structure along with further evaluation through graphs and photo documentation of structures.

3

Local scour due to water jet from a nozzle with plates

Kartal Veysi, Emiroglu M. Emin

Acta Geophysica

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2021

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Vol. 69, no. 1

95--112

EN

In this study, local scour occurring downstream from a nozzle with and without plates formed in cohesionless materials was investigated experimentally. The experiments were performed to determine scour geometry, maximum scour depth, and the efect of aeration on scour for water jets impinged obliquely into the downstream pool. Dimensionless variables afecting the scour were determined as densimetric Froude number, dimensionless impingement length, and the ratio of densimetric Froude number to dimensionless impingement length. Experiments were conducted for three nozzle diameters with plates, three nozzle diameters without plates, two diferent impingement lengths, and three diferent exit velocities. The results of the experiments showed that the use of the plates in the nozzle, jet impact velocity, jet shape, jet expansion, jet impingement length, and air entrainment rate were critical parameters for scour geometry. As a result, it was found that the jets from a nozzle with plates entrained more air bubbles into the impingement pool than jets from nozzles without plates, thereby decreasing maximum scour depth by spreading the scour over a larger area. This was evident by increasing the impingement length. In addition, scour equations were obtained to determine maximum scour depth, ridge height, and scour hole length from experimental data.

4

Environmental Aspects of Abrasive Water Jet Cutting

Perec A.

Rocznik Ochrona Środowiska

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2018

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Tom 20, cz. 1

258--274

EN

Traditional method of production has a negative impact on the environment by cutting and erosion products (chips and microchips), the used coolant (oils and emulsions, enriched aggressive chemicals) and high energy consumption. Modern systems for mechanical processing should be minimal this impact. This paper presented a study of advanced machining – Abrasive Water Jet (AWJ) technology in environmental aspects. Unlike traditional machining (grinding, milling) water jet cutting does not emit into the environment any dust or particles that are harmful if inhaled. Also presents an analysis of the fragmentation garnet – commonly used abrasive in this technology, ilmenite and olivine, and identified recycling potential of these abrasives.

PL

Tradycyjne metody produkcji mają negatywny wpływ na środowisko poprzez emisję produktów ubocznych procesu cięcia i erozji (wióry i mikrowióry), zużytej cieczy chłodząco-smarnej (oleje i emulsje, wzbogacone agresywnymi związkami chemicznymi) oraz wysokie zużycie energii. Nowoczesne systemy do obróbki mechanicznej powinny minimalizować ten wpływ. W artykule przedstawiono analizę zaawansowanej technologii produkcji – cięcia wysokociśnieniową strugą wodno-ścierną w aspekcie ochrony środowiska. W przeciwieństwie do tradycyjnej obróbki skrawaniem (szlifowanie, frezowanie) cięciu strumieniem wody nie towarzyszy emisja do środowiska pyłu i cząsteczek materiałów, które są szkodliwe. W artykule przedstawiono także analizę rozdrobnienia granatu – ścierniwa najczęściej stosowanego w tej technologii oraz ilmenitu i oliwinu oraz określono ich potencjał recyklingu.

5

Wpływ procesów cięcia termicznego i strumieniem wody na własności i jakość powierzchni ciętych stali ulepszonej cieplnie S 960QL

Górka J.

Stal, Metale & Nowe Technologie

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2016

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nr 11-12

18--24

PL

W artykule opisano wpływ procesu cięcia plazmą powietrzną, strumieniem tlenu, wiązką laserową oraz strumieniem wody na jakość powierzchni stali ulepszonej cieplnie S 960QL o grubości 10 mm. Ocenie poddano jakość powierzchni po cięciu (odchyłkę prostopadłości, chropowatość powierzchni, kąt ukosu), szerokość szczeliny cięcia, sposób przebijania oraz zmiany strukturalne i zmiany twardości przy powierzchni cięcia.

EN

In the paper, the influence of air plasma, oxygen stream, laser beam and water jet cutting processes on the surface quality of the S 960QL toughened steel has been presented. The assessment includes: surface quality (perpendicular deviation, surface roughness, scarf angle), gap width after cutting, punching method, as well as structural and hardness changes near the cutting surface.

6

O cięciu wodą w przemyśle

Świat Obrabiarek i Narzędzi

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2014

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R. 9, nr 11-12

12

7

The research into the quality of rock surfaces obtained by abrasive water jet cutting

Młynarczuk M., Skiba M., Sitek L., Hlavacek P., Kozusnikova A.

Archives of Mining Sciences

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2014

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Vol. 59, no. 4

925--940

EN

In recent years, water jet cutting technology has been being used more and more often, in various domains of human activity. Its numerous applications include cutting different materials - among them, rock materials. The present paper discusses the results of the research that aimed at determining - in a quantitative manner - the way in which the water jet cutting parameters (such as the traverse speed of the head, and the distance between the high-pressure inlet of the water jet and the cut material) influence the quality of the processed surface. Additionally, the impact of these parameters on the surface of various materials was investigated. The materials used were three granites differing with respect to the size of grains. In the course of the research, the standard parameters defined by the ISO norms were analyzed. It was also proposed that variograms be used to analyze the quality of the cut surface.

PL

Technologia cięcia strumieniem wodnym staje się w ostatnich latach coraz intensywniej wykorzystywana w różnych dziedzinach działalności człowieka. Jest ona wykorzystywana do obróbki różnorodnych materiałów, również materiałów skalnych. W ramach badań analizowano trzy granity różniące się m.in. wielkościami ziarn, które były przecinane przy różnych prędkościach przesuwu głowicy z wlotem strumienia wodnego. Analizowano standardowe parametry zdefiniowane w normach ISO jak również zaproponowano wykorzystanie wariogramów do analizy jakości wyciętej powierzchni. W pracy opisano w sposób ilościowy zmiany jakości powierzchni skał ciętych strumieniem wodnym ze ścierniwem w zależności od prędkości przesuwu głowicy, jak również w zależności od odległości przecinanego fragmentu powierzchni od wlotu strumienia wodnego do materiału. Wyniki uzyskane w pomiarach wskazują też na wpływ wielkości uziarnienia skały na jakość otrzymanej powierzchni. Jest to szczególnie widoczne dla najmniej optymalnych parametrów cięcia strumieniem wodnym, czyli dla dużych prędkości cięcia i dla fragmentów powierzchni znacznie oddalonych od brzegu próbki. W badaniach wykazano, że przy optymalnie dobranych parametrach obróbki wpływ wielkości ziarn na jakość powierzchni jest niewielki, a niekiedy nawet pomijalny. W pracy opisano również możliwość zastosowania funkcji madogramu do analizy jakości obrabianej powierzchni. Przy wykorzystaniu tej funkcji można nie tylko potwierdzić rezultaty otrzymane na bazie parametrów zdefiniowanych w ISO, ale otrzymuje się bardziej dogłębny obraz ukształtowania badanej powierzchni.

8

Dependency of The Technological Quality of Elements Made From An Aluminum Alloy on Their Shape in The Water Jet Machining

Wantuch E., Kudelski R., Nieciąg H.

Journal of Machine Engineering

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2013

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Vol. 13, No. 4

35--46

EN

The problem of the technological quality of elements is one of the primary problems of modern machine production. In many cases, elements are made from new construction materials with specific properties considered to have poor machinability in cases where conventional technologies are applied. Thus, there is a need to identify the capabilities of new technologies, including the technology of cutting with a high-pressure abrasive water jet for the production of elements made of Al alloys, while observing qualitative machining requirements. This paper presents the results of studies of the accuracy of production of elements with a complex shape made of a 2017A alloy (PA6) and of studies of the coarseness of obtained surfaces depending on the pressure of the water jet, cutting advance rate, and the amount of dosed abrasive for a constant thickness of the element. The measure of the accuracy of production, independent of dimensional accuracy, was assumed to be the size of chamfering on the side surface of the cut element caused by a specific mechanism of material decohesion occurring under the influence of water jet technology. In cases where Al alloys are cut, depending on assumed conditions, it is possible to shape the side surface of an element with a positive, negative, or neutral (zero) wall inclination (side of the element). In the process of cutting, specific errors in the shape of the element occur and appear on curved fragments of the object or in discontinuous areas of the profile (e.g. transition from a straight fragment to an arc fragment); this is caused by a shift in the exit of the high-pressure abrasive water jet from the object relative to the point of entry. Consequently, selection of cutting parameters for the water jet method for elements with complex shapes is, in essence, a compromise between the obtained inclination of the wall of the processed element and the required surface coarseness, and between the required (acceptable) inclination of the wall of the element or lack thereof and the obtained coarseness of the elements surface. Thus, in the outlined problem, it is not possible to simultaneously obtain two satisfactory criteria quantities of element quality, that is, accuracy of shape and requisite coarseness of the surface of the machined element, if the water jet method is applied for the purpose of machining Al alloys.

9

Economic efficiency of engineering material cutting technologies

Micietova A., Cillikova M., Salaj J.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 2

369-375

EN

Non-conventional methods are used more and more frequently for metal cutting in practice. Some methods such as laser cutting and abrasive water jet cutting are very often applied. Economic and ecological factors strongly influence the application of a method chosen for the cutting process. Considering the economic efficiency there should be formulated a cost model for comparison of different methods of metal cutting. This model should involve all aspects influencing the cutting process. This paper deals with the analysis of important cost items when a material is cut by oxygen , laser and water jet.