32results about How to "Avoid running out quickly" patented technology

The invention discloses a method for carburizing the surface of cemented carbide, which is characterized in that it first heats the temperature at 550-700°C for 1-2 hours to form a cemented carbide blank containing carbide-forming elements; 2 o 3 coated TiH 2 Core / shell structure powder with thickness less than 3nm, number of layers less than 3 and specific surface area greater than 250m 2 / g of graphene and two substances are mixed according to the weight percentage of 2:3 to prepare a hydrogen-containing carburizing medium; then the green body is embedded in the hydrogen-containing carburizing medium and compacted under a pressure of 5~15MPa; finally, the liquid phase Sintering to realize carburizing of cemented carbide surface. The invention overcomes the problems of severe crystal grain growth, long carburizing time and low efficiency in the prior art, and realizes carburizing of the hard alloy surface in the sintering process.

The invention discloses a method for preparing surface carburized gradient cemented carbide, which is characterized in that it first heats the temperature at 550-750°C for 2-4 hours to form a cemented carbide product with a porosity of 25%-40% and removes the forming agent. blank; then SiO2-coated TiH2 core / shell structure powder, graphene with a thickness of less than 3nm, a number of layers less than 3 layers and a specific surface area greater than 250m2 / g, and BaCO3 are prepared by mixing 1:2:1 by weight percentage Hydrogen-containing carburizing medium; then the green body is buried in the hydrogen-containing carburizing medium and compacted under a pressure of 5-15MPa; finally, liquid-phase sintering is carried out to prepare a surface-carburized gradient cemented carbide. The invention overcomes the problems of serious grain growth, long carburizing time and low efficiency in the prior art, and prepares surface carburized gradient hard alloy in the sintering process.

The invention discloses an in-situ preparation method of surface carburized hard alloy, which is characterized in that it first heats the temperature at 550-700°C for 1-2 hours to form a hard alloy body containing carbide-forming elements; then wraps Al2O3 TiH2-coated core / shell structure powder, multi-walled carbon nanotubes with an outer diameter of less than 8nm, a length of less than 30μm and a specific surface area greater than 350m2 / g, and BaCO3 are mixed at a weight percentage of 2:3:1 to prepare hydrogen-containing carburizing medium; then embed the green body in a hydrogen-containing carburizing medium and compact it under a pressure of 5-15 MPa; finally, carry out liquid phase sintering to prepare a surface carburized cemented carbide. The invention overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the existing technology, and realizes in-situ preparation of surface carburized hard alloy in the sintering process.

The invention discloses a preparation method of self-lubricating surface Ti (C, N)-based metal ceramic based on a metal hydride. The method is characterized by comprising the following steps: firstly performing heat preservation for 1 to 2 h at 500 to 700 DEG C, so as to form a metal ceramic body containing carbide forming elements; and then mixing core / shell structure powder of Al2O3 coated TiH2, a multiwalled carbon nanotube with the external diameter being smaller than 8 nm, the length being smaller than 30 micrometers and the specific surface area being greater than 350 m<2> / g, and NaHCO3 according to a weight percentage of 3:2:1, so as to prepare a hydrogen-containing carburizing medium; embedding the metal ceramic body into the hydrogen-containing carburizing medium, and performing compaction at 5 to 15 MPa; and finally performing liquid-phase sintering, so as to prepare the self-lubricating surface Ti (C, N)-based metal ceramic. The method overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the prior art, and realizes the preparation of the self-lubricating surface Ti (C, N)-based metal ceramic during a sintering process.

The invention discloses a method for preparing cemented carbide with a graphite-rich surface, which is characterized in that it first heats at 550-700°C for 1-2 hours to form a cemented carbide body containing carbide-forming elements; then amorphous Si-C ‑O core / shell structure powder coated with TiH2, graphene with a thickness of less than 3nm, a layer number of less than 3 layers and a specific surface area greater than 250m2 / g, and NaHCO3 are mixed according to weight percentage 2:3:1 to prepare a hydrogen permeable carbon medium; then embed the green body in a hydrogen-containing carburizing medium and compact it under a pressure of 5-15MPa; finally carry out liquid phase sintering to prepare a cemented carbide with a graphite-rich surface. The invention overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the existing technology, and realizes the preparation of hard alloy with graphite-rich surface in the sintering process.