Sintered carbides

Testing of linear variation of hardness allows us to check the effectiveness of complex technological processes in the ceramics industry. As an example, we consider the results obtained by van Naderveen (1980) for sintered carbide layers superposed on cylindrical items of soft steel in cold... 

Interesting are attempts to design dynamic hardness testers with a higher level of automation. Among these, we should mention the Equotip hardness tester manufactured by Proceq of Switzerland and the Sonodur A probe manufactured by Branson-Krautkramer. In the former, the sampler in the shape of a ball of sintered carbide is mounted in a beater weighing 5.5 g, which is also fitted out with a permanent magnet. This enables measurement of the speed of impulse and rebound by proportional current induction in the measuring coil. The quotient of rebound and impulse speed multiplied by 1000 is defined as hardness L (after the name of the method s author—Leeb). The hardness measurement result L can be converted to HKC, Hb or Hv with the aid of tables. 

Peters intentionally changed the structural factors fc and d, and thus A, and found in the material close dependence of the toughness of sintered carbides, calculated from Palmquist cracks, on the free-mean-path (Table... 

The kinetics of diamond powder infiltration with cobalt of VK15 sintered carbide and Co-Mo and Co-Ti melts was studied experimentally at 8 GPa (Fig, 1). Confidence intervals for T and k values, the reliability being a= 0,95, do not exceed 8 %. According to [3], the limit of WC solubility in Co attains 10 mass % or 3.2 at. %. The additive contents of Co-Mo and Co-Ti alloys was 10 mass % (accordingly, the atomic portions were 0.12 Ti and 0,064 % Mo). Samples of alloys were sintered from mixtures of cobalt-molibdenum and cobalt-titanium hydride powders in a vacuum furnace at 1000 °C. 

V.I.Tretyakov. Fundamentals of Metal Science and Technologies of Sintered Carbide Production [in Russian], Metallurgiya, Moscow, 1976. 

In an earlier patent Crosby and coworkers described CVD processes of volatile ruthenium / -diketonates (Ru(acac)3, Ru(tfac)3, Ru(hfac)3 etc.) on heat resistant substrates such as sintered carbides (WC/TiC/TaNbC/Co) in a low-pressure atmosphere. ... 

This method is suitable for flat shapes with a height to diameter ratio less than unity. In the direction of the compression, the shape must not be profiled since the material has little tendency to flow. The method has the advantage of providing dimensional accuracy, saving of heat in drying, and the possibility of automation. The dies are usually of steel, sometimes special alloys, and possibly partly sintered carbides because some mixes have strong abrasive properties. 

There is yet another way to suppress excessive grain growth and thus to attain high relative densities. It is provided by hot pressing (sintering under pressure), which is used particularly in the manufacture of sintered carbides and nitrides. Even at high temperatures, these substances show low atom mobility so that spontaneous... 

Iron Age, New York, Direetoiy of Tool, Die Steels and Sintered Carbides. ... 

Figure 15-6. Comparison of observed and calculated temperatures for the chip-tool interface in metal cutting. From data by Loewen and Shaw [13] for sintered carbide cutting AISI B1113 steel.

General purpose for all types of material Sintered carbide, Non-oxide ceramics Cermets, Natural stone (polishing)... 

The bit is made of sintered carbide (sharp edge) and steel. Stochastic influences of material parameters of the bit can be neglected. 

Fig. 51. X-ray diffraction pattern of the powdered cobalt- rial can be detected in the sample, SiOj modifications innickel alloy from the sintered carbide metal production of the eluded. Courtesy of Dr. R.-W. Schliephake, Bergbau-...

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