When it was heated in air, so all components must burn with the formation of powdery WO3, CuO/Cu2O, SiO2 and gaseous CO2. When it was heated in an inert gas, so only oxidized silicon with formation of SiO2.

Produces a sintered body from powder compact or not (only with inert gas or vacuum sintering!)  also depends on the grain size of the components. Fine-grained silicon and carbon prevent the sintering, but fine-grained copper will promote sintering.

I agree with Vadim. Your discribtion sounds that you have sintered under air atmosphere. This is definitely impossible. Even under a protective gas atmosphere or under vacuum I have my doubts that you will achieve an acceptable result, because the sintering temperature might be too low. This depends very strongly on the particle size distribution of the single components. The cold pressure and the pressing methode before sintering are also important. To achieve full density a liquid phase mighr be necessary or a hot pressing process. The whole case is too complicated to explain with a few sentences. A guess that you are not a powder metallurgist. If yes you should start with literature research on powder metallurgical principals first, before continuing sintering trials. For details you can contact me anytime.

Thanks Dr. Vadim and Dr. Christian for your inputs.

i will contact you son in this regard.

this phenomena is the self combustion (SHS reaction) between tungsten and carbon powders. this burning would occur even if you do this in protective atmosphere.

Dear Mohit,

The how to perform sintering of tungsten and carbon powder? Pls help me in this regards,

thanking you

The copper sinter in the presence of air forms CuO / Cu2O. The presence of impurities or diffusion of other ions decreases the melting point of these oxides. As commented by researchers sintering must take place in an inert atmosphere. However, it should substantially reduce this pre sintering temperature due to intrinsic impurities.