scholarly journals Chip Formation and Machinability of Nickel-Base Superalloys

2011 ◽  
Vol 278 ◽  
pp. 460-465 ◽  
Author(s):  
Carsten Siemers ◽  
Badya Zahra ◽  
Dawid Ksiezyk ◽  
Pawel Rokicki ◽  
Zdeněk Spotz ◽  
...  
Keyword(s):  
Formation Process ◽  
Chip Formation ◽  
High Speed ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Orthogonal Cutting ◽  
Oil And Gas Industry ◽  
Alloy 625 ◽  
Nickel Base Superalloys ◽  
Nickel Base

Nickel-base superalloys like Alloy 625 are widely used in power generation applications and in the oil and gas industry due to their unique properties especially at elevated temperatures. The chip formation process of Alloy 625 is not yet well understood. Therefore, the cutting process of this alloy has been studied in detail by means of orthogonal cutting experiments at conventional cutting speeds and in the high-speed cutting regime. Alloy 625 shows a cutting parameter dependent change in the chip formation process from continuous to segmented chips. Silver has been added to Alloy 625 to improve the machinability. During machining of these modified alloys short breaking chips develop so that cutting processes are eased and can be automated.

Finite Element Analysis of the Influence of the Material Constitutive Law Formulation on the Chip Formation Process During a High Speed Metal Cutting

2012 ◽  
Author(s):  
Adinel Gavrus ◽  
Pascal Caestecker ◽  
Eric Ragneau
Keyword(s):  
Finite Element ◽  
Formation Process ◽  
Chip Formation ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Constitutive Law ◽  
Cutting Process ◽  
Contact Friction ◽  
Numerical Predictions

During the last decades, the importance of machining in manufacturing industry has required rigorous scientific studies concerning the chip formation process in order to determine optimal speeds, feeds or other technological parameters. For all types of machining including turning, milling, grinding, honing or lapping, the phenomenon of chip formation is similar in terms of the local interaction between the tool and the work piece. Because of the intensive use of CNC machine tools producing parts at ever-faster rates, it has become important to provide analysis of high speed cutting where complex loading conditions occur during the fabrication process: high gradients of the thermo-mechanical variables, strong nonlinearities of the thermo-mechanical coupling, large plastic strains, extremely high strain rates compared to that of other forming processes, important influence of the contact friction and of the microstructure evolution. Today many scientific researches are focalized on finite element analyses of the chip formation and of its morphology evolution during a high speed metals cutting process. To improve the quality of the numerical predictions, a better description of the local shear band formation is needed, using adequate rheological models. On this point of view this paper deals with the influence of the rheological behavior formulation on the morphology and geometry of the chip formation during a finite element simulation of a high speed metal cutting process. Numerical simulations of a high speed orthogonal cutting of special steels are employed to analysis the sensitivity of the numerical results describing the local cutting area with respect to different rheological laws: Norton-Hoff or Cowper-Symonds model, Johnson-Cook one or Zerilli-Armstrong formulation. To obtain a better description of the local material loadings and to take into account the important gradient of the strain rate, plastic strain and temperature values, a more adequate constitutive model is proposed by the author.

scholarly journals Development of Real-Time Time Gated Digital (TGD) OFDR Method and Its Performance Verification

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4865
Author(s):  
Kinzo Kishida ◽  
Artur Guzik ◽  
Ken’ichi Nishiguchi ◽  
Che-Hsien Li ◽  
Daiji Azuma ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Fibers ◽  
High Speed ◽  
Oil And Gas ◽  
Scattered Light ◽  
Oil And Gas Industry ◽  
High Signal ◽  
Chirp Pulse ◽  
Sound Waves ◽  
Industry Applications

Distributed acoustic sensing (DAS) in optical fibers detect dynamic strains or sound waves by measuring the phase or amplitude changes of the scattered light. This contrasts with other distributed (and more conventional) methods, such as distributed temperature (DTS) or strain (DSS), which measure quasi-static physical quantities, such as intensity spectrum of the scattered light. DAS is attracting considerable attention as it complements the conventional distributed measurements. To implement DAS in commercial applications, it is necessary to ensure a sufficiently high signal-noise ratio (SNR) for scattered light detection, suppress its deterioration along the sensing fiber, achieve lower noise floor for weak signals and, moreover, perform high-speed processing within milliseconds (or sometimes even less). In this paper, we present a new, real-time DAS, realized by using the time gated digital-optical frequency domain reflectometry (TGD-OFDR) method, in which the chirp pulse is divided into overlapping bands and assembled after digital decoding. The developed prototype NBX-S4000 generates a chirp signal with a pulse duration of 2 μs and uses a frequency sweep of 100 MHz at a repeating frequency of up to 5 kHz. It allows one to detect sound waves at an 80 km fiber distance range with spatial resolution better than a theoretically calculated value of 2.8 m in real time. The developed prototype was tested in the field in various applications, from earthquake detection and submarine cable sensing to oil and gas industry applications. All obtained results confirmed effectiveness of the method and performance, surpassing, in conventional SM fiber, other commercially available interrogators.

Tool Wear Mechanisms during Machining of Alloy 625

2011 ◽  
Vol 275 ◽  
pp. 204-207 ◽  
Author(s):  
Lenka Fusova ◽  
Pawel Rokicki ◽  
Zdeněk Spotz ◽  
Karel Saksl ◽  
Carsten Siemers
Keyword(s):  
Wear Mechanisms ◽  
Gas Turbines ◽  
Metal Cutting ◽  
Elevated Temperatures ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Production Costs ◽  
Chemical Compositions ◽  
Alloy 625 ◽  
Wide Range

Nickel-base superalloys like Alloy 625 are widely used in power generation applications due to their unique properties especially at elevated temperatures. During the related component manufacturing for gas turbines up to 50% of the material has to be removed by metal cutting operations like milling, turning or drilling. As a result of high strength and toughness the machinability of Alloy 625 is generally poor and only low cutting speeds can be used. High-speed cutting of Alloy 625 on the other hand gets more important in industry to reduce manufacturing times and thus production costs. The cutting speed represents one of the most important factors that have influences on the tool life. The aim of this study is the analyses of wear mechanisms occurring during machining of Alloy 625. Orthogonal cutting experiments have been performed and different process parameters have been varied in a wide range. New and worn tools have been investigated by stereo microscopy, optical microscopy and scanning electron microscopy. Energy-dispersive X-ray analyses were used for the investigation of chemical compositions of the tool's surface as well as the nature of reaction products formed during the cutting process. Wear mechanisms observed in the machining experiments included abrasion, fracture and tribochemical effects. Specific wear features appeared depending on the mechanical and thermal conditions generated in the wear zones.

“Has Microelectronic MCM Technology Matured and is it Capable of Servicing the Widespread Needs of Down Well 225°C Operating Applications in the Oil and Gas Industry?”

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000319-000324
Author(s):  
Bob Hunt ◽  
Andy Tooke
Keyword(s):  
Thermal Shock ◽  
Thick Film ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Oil And Gas Industry ◽  
Temperature Cycling ◽  
Active Components ◽  
Gas Industry

This paper reviews development and qualification work performed on 225°C operating temperature modules based on ceramic thick film multi-layer substrates supporting embedded thick film resistors, assembled passive and active components with ‘chip and wire’ connections and sealing in hermetic metal and ceramic cavity packages. It considers aspects of development and importantly investigates product qualification which includes shock and vibration at elevated temperatures as well as thermal shock and temperature cycling. In conclusion there is an attempt to answer the question “Has microelectronic MCM technology matured and is it capable of servicing the widespread needs of down well 225 °C operating applications in the Oil and Gas industry?”

Environmentally Hardening IC Die Previously Assembled in Plastic Packages through Die Removal, Bond Pad Replating and Reassembly into Hermetic Packages

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000039-000044
Author(s):  
Charlie Beebout ◽  
Erick M. Spory
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Electroless Nickel ◽  
Oil And Gas Industry ◽  
Market Demand ◽  
Global Circuit ◽  
Bond Wires ◽  
Bond Pads

ABSTRACT Many integrated circuits (ICs) will operate well above their maximum rated temperature of +70°C or +125°C, but are often not packaged appropriately to reliably endure temperatures above +150C. Specifically, the original gold or copper bonds on the aluminum die bond pads are prone to Kirkendall or Horsting voiding, particularly at temperatures greater than +150°C. Also the mold compounds used in plastic packaging for IC assembly can degrade at these elevated temperatures. In some cases, commercial demand for higher temperature reliability can justify a separate offering of ICs assembled in hermetic, ceramic packages from the original component manufacturer (OCM). However, in most cases, the market demand is deemed insufficient. Global Circuit Innovations (GCI) has developed a high-yielding process, which can remove a semiconductor die (i.e., computer chip) from a plastic package, remove the original bond wires and/or ball bonds, plate the aluminum die bond pads with Electroless Nickel, Electroless Palladium, and Immersion Gold (ENEPIG), and then reassemble the now improved semiconductor die into a hermetic, ceramic package. Device Extraction, ENEPIG die bond pad plating and Repackaging (DEER) provides an improved die bond pad surface such that works well with either gold or aluminum bond wires in applications up to +250°C without mechanical or electrical connectivity degradation. GCI routinely exposes sample devices to +250°C bakes with 100% post bake yields so as to continuously ensure that any device processed with the DEER technology will reliably perform in high-temperature environments. Although the oil and gas industry has already expressed significant interest in the DEER process, with excellent lifetest and production application results demonstrating dramatically increased component lifetimes at elevated temperatures, this technology can also be leveraged for any application exposing ICs to harsh environments. Not only is the high-temperature reliability dramatically increased, but also the new hermetic, ceramic package protects the IC from a variety of elements and environments (i.e., corrosives and moisture).

scholarly journals Mechanism of Chip Formation Process at Grinding

2019 ◽  
Vol 297 ◽  
pp. 09002
Author(s):  
Vyacheslav Shumyacher ◽  
Sergey Kryukov ◽  
Olga Kulik ◽  
Xavier Kennedy
Keyword(s):  
Formation Process ◽  
Chip Formation ◽  
High Speed ◽  
Cutting Speed ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Abrasive Grain ◽  
Wave Heating ◽  
High Speed Grinding

The mechanism of chip formation process at grinding is described, which involves a high-speed interaction of abrasive grain and metal, which leads to a concentration of thermal energy in front of the dispersing element (grain), causing a locally concentrated shift in the metal microvolume. In “abrasive grain -metal” contact a dissipative structure is formed which existence is supported by exchange of energy and substance with environment. Due to shock compression of the metal microvolume with abrasive grain, shock-wave heating is realized, initiating emission of electrons ionizing the lubricating cooling fluid in the zone of formation of side micro-scratches left by abrasive. The results obtained in the course of the research can be used to explain the mechanisms of chip formation, as well as the course of the physical and mechanical processes occurring on the surface layers of the grinded workpieces. By controlling chip formation processes at high-speed grinding, by optimally selecting the appropriate ratios between cutting speed and other processing parameters, a reduction in process thermal density can be achieved, which, with the highest productivity, will allow to obtain the required quality of the surface layer of the workpieces and a given dimensional accuracy.

scholarly journals THE INFLUENCE OF ETHYLENE COPOLYMERS WITH VINYL ACETATE ON PROPERTIES OF RUBBER BASED OF BUTADIENE-NITRILE CAOUTCHOUC

2018 ◽  
Vol 61 (8) ◽  
pp. 59
Author(s):  
Ivan S. Spiridonov ◽  
Marina S. Illarionova ◽  
Nikolay F. Ushmarin ◽  
Sergei I. Sandalov ◽  
Nikolay I. Kol'tsov
Keyword(s):  
Vinyl Acetate ◽  
Oil And Gas ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Oil And Gas Industry ◽  
Petroleum Products ◽  
Standard Samples ◽  
Rubber Mixture ◽  
Gas Industry ◽  
Technical Products

Rubber-technical products, which are used in the oil and gas industry, must have high thermal and aggressive strength. Rubbers based on butadiene-nitrile caoutchoucs are usually used for these purposes, since they have good operational properties. However, under the influence of elevated temperatures, the resistance of such rubbers to the action of petroleum products is reduced, as a result of which the physico-mechanical characteristics decrease. To improve the operational properties of rubber-technical products, various technological additives are introduced into the rubber mixtures. Such additives can be copolymers of ethylene with vinyl acetate(EVA), which increase the resistance of rubbers to action of high temperatures and aggressive media. This is due to the fact that these copolymers are well combined with butadiene-nitrile caoutchoucs, forming coordination bonds with rubber molecules, which contributes thereby increasing in the elastic-strength and performance properties of rubber. In this connection, the influence of EVA (sevillenes 11104-030, 11808-340 and MarPol 1802), differing in the content of vinyl acetate units, on the rheometric, physico-mechanical and operational properties of the rubber mixture based on butadiene-nitrile rubber in this paper was investigated. The study was carried out to improve the thermo-resistance of rubber used for the manufacture of oil and petrol resistant rubber-technical products for the oil and gas industry. The rubber mixture was prepared on laboratory rolls and standard samples were vulcanized in an electrically heated press. The study of rheometric properties has shown that EVA affect the characteristics of the vulcanization process of a rubber mixture. For vulcanizates, the influence of the content of EVA in a rubber mixture on the physical and mechanical properties was studied: the conditional tensile strength, elongation at break, tear resistance, rebound elasticity, Shore A hardness, relative compression deformation. The effect of the standard liquid ZHR-1 on the change in these properties, as well as the degree of swelling of the vulcanizates after their daily soaking in the standard liquid SZHR-1 and a mixture of isooctane + toluene, was studied. It has been established that vulcanizate of a rubber mixture containing sevilene 11808-340 is characterized by the best physico-mechanical and operational properties.

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