In forming tungsten carbide layer by low temperature and vacuum CVD, uniformity of film thickness, adhesion and gloss achieved when the effective zone of coating set is increased to 4450 x 1,100mm is described. Characteristics of tungsten carbide layer are evaluated and compared with other materials. Some practical applications to the mechanical parts of plastic injection molding machines are i...

Cemented carbides, including coated cemented carbides, account for 75% of the cutting tools market because of their features such as high hardness, toughness, and the responsiveness to iron, through the use of tungsten carbide for their main hard phases and cobalt for their bonding metals. The consumption of tungsten continues to increase as the amount of carbide tool production increases with ...

OBJECTIVES To assess the exposure to tungsten, cobalt, and nickel in a plant producing hard metals. The main components of hard metals are tungsten carbide and cobalt metal. According to recent studies, these two components may be responsible for both fibrogenic and carcinogenic effects. METHODS 87 workers were investigated (86 male, one female) with a median age of 42 (range 22-58) and a mea...

For the first time, both X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) techniques were applied in analysis of surface contamination of electrochemically etched Scanning Tunneling Microscope (STM) tungsten tips. Carbon monoxide, graphite, tungsten carbide and tungsten oxide were found as main surface contaminations of STM tungsten tips. The thickness of tungsten ox...

Tungsten-containing amorphous carbon films were produced by dual magnetron sputter deposition. The formation of carbide phases after heat treatment in inert gas at temperatures up to 2800 K was investigated by X-ray diffraction for tungsten concentrations below 25 at%. After deposition, each film consists of an amorphous carbon matrix with atomically dispersed W inclusions. Annealing up to 2800...

The purpose of this study was to evaluate the durability of tungsten carbide burs for the fabrication of titanium crowns using two dental CAD/CAM systems (DECSY, Digital Process, Japan and Cadim, Advance, Japan). A tungsten carbide bur in each system was examined and used without fracture to fabricate 51 titanium crowns. For both systems tiny chips were found on the bur blade at the 11th machin...

Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to measure the concentrations of cobalt, tantalum, titanium, vanadium and chromium in solutions of tungsten carbide. The main advantage of the method described here lies in the speed, convenience and effectiveness of the dissolution procedure. Aliquots of powdered tungsten carbide were dissolved in a solution of 5% aqua...

igh-temperature corrosion/oxidation has been shown to be a major contributor to the wear of tungsten carbide when machining medium density fiberboard (MDF) (Stewart 1992). Consequently, a change in the properties of the tool material to resist wear from the adverse wood machining environment needs to be investigated. A deep cryogenic treatment shows promise as a tool material treatment for incr...

BACKGROUND The present study aimed at 3D analysis of adhesive remnants and enamel loss following the debonding of orthodontic molar tubes and orthodontic clean-up to assess the effectiveness and safety of One-Step Finisher and Polisher and Adhesive Residue Remover in comparison to tungsten carbide bur. MATERIALS AND METHODS Thirty human molars were bonded with chemical-cure orthodontic adhesi...