Low‐Temperature Preparation of Titanium Carbide Coatings on Graphite Flakes from Molten Salts

Abstract

Titanium carbide (TiC)‐coated graphite for refractory castable applications was prepared via reacting titanium metal powder (∼45 μm) and natural graphite flakes (100–300 μm) for 5 h at 950°C in a KCl‐based salt in Ar atmosphere. TiC coatings formed on graphite flakes were uniform, crack‐free, and composed of nanosized particles (20–40 nm). The “template‐growth” mechanism played a dominant role in the coating formation process.

Low‐temperature preparation of titanium diboride fine powder via magnesiothermic reduction in molten salt

“…As well‐documented in the literature, depending on the solubility values of reactants in the molten salt, two main mechanisms, “template‐growth” and “dissolution and precipitation,” generally function in an MSS process. Although the exact solubility values of B and Ti in molten chloride salts are not known, based on our previous MSS work on TiC coating preparation, and recent MSS studies on ZrB 2 and B 4 C coating preparation (K. Bao & S. Zhang, unpublished work), it is considered that both B and Ti could at least partially dissolve in the molten chloride salts (though the actual solubility might be very small). So during the reaction process, B and Ti from Reactions would slightly dissolve in the molten chloride salt and then react with each other in it rapidly, forming TiB 2 product according to Reaction via a “dissolution‐precipitation” mechanism.…”

Spinel‐Coated Graphite for Carbon Containing Refractory Castables

“…Figure 1(a) is the XRD pattern of the as‐received graphite, showing the characteristic peaks at around 27° and 55° 11 . The SEM micrograph in Fig.…”

“…Some scientists preferred to passivate aluminum powder with mineral oil or PVA, 9,10 although it may introduce excess porosity into the castable and contaminate steel with residual carbons. Zhang and colleagues recently developed a promising technique for coating graphite with TiC, but no report is still available on the characteristics of castables prepared with such graphites 11 . Yoshimatsu et al 12 .…”

Significant improvement of refractoriness of Al2O3–C castables containing calcium aluminate nano-coatings on graphite

“…A secondary problem of atmospheric pollution arises due to emission of carbon monoxide (CO) and/or carbon dioxide (CO 2 ) gases because of prevailing oxidizing atmosphere at the application site. Surface modification of graphite has thus been adopted by many researchers with a desire to reduce water content of batch and minimize rate of emission of carbonaceous products by environmentally benign manner [5,6,7]. The use of novel forms of carbon materials e.g.…”