High-Temperature (250 °C / 500 °F) 19 000 min $^{\hbox{-}1}$ BLDC Fan for Forced Air-Cooling of Advanced Automotive Power Electronics

Thermal barrier coatings (TBCs) consist of a multi-layered system where the different layers are deposited to improve the high temperature capability of the underlying substrate material. Substrate materials are usually made of Ni-based superalloys which have an outstanding combination of high-temperature strength, toughness and resistance to degradation in corrosive or oxidizing environments. In this study, the effect of different substrate materials on cyclic TBC lifetime has been studied by using two different superalloys, IN100 and CMSX-4, as the substrate materials. Two different ceramic topcoat materials, 7wt. % yttria partially stabilized zirconia (7YSZ) and Gadolinium Zirconate (GdZ), have been deposited on NiCoCrAlY bond coats. All depositions in this study have been carried out by Electron Beam Physical Vapor Deposition (EB-PVD). Lifetime measurements have been done by holding the systems at 1100°C for 50mins and then reducing the temperature to ambient level by forced air cooling for 10mins. The TBC lifetime in case of IN100 substrates is higher than on CMSX-4. The use of GdZ as topcoat material improves the lifetime for both IN100 and CMSX-4 based TBC systems, however, the lifetime for CMSX-4 based TBC system is still shorter than its IN100 counterpart. In this study, lifetime comparisons, changes in the microstructure and diffusion of different elements in the system are investigated.

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ALLEGHENY STAINLESS TYPE 405

Alloy Digest ◽

10.31399/asm.ad.ss0461 ◽

1985 ◽

Vol 34 (7) ◽

Keyword(s):

Fracture Toughness ◽

Corrosion Resistance ◽

High Temperature ◽

Critical Temperature ◽

Physical Properties ◽

Tensile Properties ◽

Heat Treating ◽

Ductile Material ◽

Air Cooling ◽

Temperature Performance

Abstract ALLEGHENY STAINLESS Type 405, unlike most other 12% chromium steels, is not subject to appreciable hardening through air cooling from high temperatures. This is an advantageous characteristic in those applications where a soft, ductile material is required after rapid cooling from above the critical temperature. The nonhardening tendency of Type 405 also retards the formation of hardening cracks where welding is employed. Its uses include annealing boxes and baffles where hardening during cooling would be undesirable. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as heat treating and machining. Filing Code: SS-461. Producer or source: Allegheny Ludlum Corporation.

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Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

Endoscopy International Open ◽

10.1055/a-1336-3280 ◽

2021 ◽

Vol 09 (03) ◽

pp. E482-E486

Author(s):

Stanislas Chaussade ◽

Einas Abou Ali ◽

Rachel Hallit ◽

Arthur Belle ◽

Maximilien Barret ◽

...

Keyword(s):

Light Source ◽

Cooling System ◽

Air Cooling ◽

Airborne Transmission ◽

Plastic Tube ◽

Care Workers ◽

Air Cooling System ◽

Forced Air ◽

Air Circulation ◽

Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

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