Development of Precision Spraying Systems Combined with Machining. (1st Report). Improvement in Bond Strength of Ceramic Coatings by the Clean-cut Plasma Spraying.

Plasma spraying and characterization of chromium carbide – nickel chromium coatings

Chromium carbide – nickel chromium powder Cr3C2-25wt.NiCr was plasma sprayed by a water-stabilized system WSP®. A series of experiments with variable feeding distance was carried out. Basic characterization of coatings was done by XRD, SEM and light microscopy plus image analysis. Microhardness was measured on polished cross sections. The main focus of investigation was on resistances against w...

the survey of the virtual higher education in iran and the ways of its development and improvement

این پژوهش با هدف "بررسی وضعیت موجود آموزش عالی مجازی در ایران و راههای توسعه و ارتقای آن " و با روش توصیفی-تحلیلی و پیمایشی صورت پذیرفته است. بررسی اسنادو مدارک موجود در زمینه آموزش مجازی نشان داد تعداد دانشجویان و مقاطع تحصیلی و رشته محل های دوره های الکترونیکی چندان مطلوب نبوده و از نظر کیفی نیز وضعیت شاخص خدمات آموزشی اساتید و وضعیت شبکه اینترنت در محیط آموزش مجازی نامطلوب است.

Solution and Suspension Plasma Spraying of Nanostructure Coatings

Air-plasma spraying colloidal solutions of nanosized ceramic powders

Coatings prepared from nanosized powders were obtained by spraying ethanol-based colloidal solutions into a plasma plume. The powders investigated included 40 nm γ -Al2O3, 75 nm 8 wt% Y2O3-ZrO2, and 750 nm 25 wt% CeO2-ZrO2. Spray distances from approximately 50 to 63 mm were required to achieve significant coating deposition. As observed in the TEM, the typical lamella morphology of air plasma ...

Plasma spraying of micro-composite thermal barrier coatings

The thermal barrier coatings (TBCs) by gas tunnel-type plasma spraying exhibited ceramic-composite features consisting of a host oxide matrix ceramic with an embedded second phase material. The densities of the composite TBC were found to be higher than those sprayed with 100wt% ZrO2 or Al2O3. In the coatings produced with powder mixtures of 50wt%, the embedded splats are found to have a relati...