High Temperature In Situ Antioxidation Coating Fabricated by AAC Method

2013 ◽  
Vol 537 ◽  
pp. 42-45
Author(s):  
Zhen Ting Wang ◽  
Gang Liang ◽  
Guo Gang Zhao
Keyword(s):  
High Temperature ◽  
Composite Coating ◽  
Oxygen Diffusion ◽  
Graphite Electrode ◽  
Raw Materials ◽  
Graphite Substrate ◽  
Ceramic Particles ◽  
Cladding Layer

In the surface of graphite electrode, the in-situ synthesized high temperature antioxidation composite coating is prepared, depending on argon arc cladding and the raw materials of Si and B4C powder. The coating consists of SiC and B13C2ceramic particles. The results show that: the reaction generates B2O3and SiO2with high temperature play a role in healing crack and preventing oxygen diffusion; a kind of continuous interface is present between the cladding layer and the graphite substrate, no obvious flaws; burning at 1573 K and 10 h, oxidation weightlessness rate is 0.912%.

scholarly journals In Situ Observation of the Carbothermic Reduction and Foaming of Slags in Silicomanganese Production

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2020
Author(s):  
Vincent Canaguier ◽  
Merete Tangstad
Keyword(s):  
Carbothermic Reduction ◽  
Sessile Drop ◽  
Raw Materials ◽  
Reduction Reaction ◽  
Furnace Operation ◽  
Graphite Substrate ◽  
In Situ Observation ◽  
High Carbon ◽  
Slag Droplet

The carbothermic reduction of slag in silicomanganese production is accompanied by the release of carbon monoxide. This gas can accumulate as bubbles within the slag, leading to foaming and, potentially, disturbances to furnace operation. This study investigated the reduction in the slag together with its foaming using a sessile drop furnace. Five silicomanganese slags produced from industrial raw materials (Assmang ore, Comilog ore, high-carbon FeMn slag with quartz, and FeS additions) were reduced by a graphite substrate at isothermal conditions (i.e., 1540–1660 °C) under CO atmosphere. The reduction reaction was tracked by photographing the slag droplet, and the cyclic expansion and burst of the droplet were used to estimate the gas evolution. The reacted samples were analyzed by wavelength-dispersive X-ray spectroscopy (WDS) to determine MnO and SiO2 reduction. While no foaming was observed using Comilog ore, extensive retention of CO in the slag phase was observed when using Assmang ore or Assmang with high-carbon FeMn slag. The beginning of foaming was attributed to an increase in the reaction rate; the absence of foaming when using Comilog can be attributed to the acidity of the charge. Addition of sulfur to the Comilog-based charge did not influence the reduction.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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