Abstract: Disclosed is an apparatus for producing composite gas used for fabricating nanocomposite materials. The apparatus includes a pressure tank having a housing, which has an internal space and an upper opening, and a closing cap opening or closing the opening, a carrier mounted below the housing, a gas supply supplying inert gas into the pressure tank, a powder supply mounted to the closing cap to supply nano-powders into the pressurized inert gas tank, an exhaust part discharging the inert gas containing nano-powders supplied into the pressure tank, an upper rotor disposed to the inner side of the closing cap, and a lower fan mounted at a lower portion of the housing.

Abstract: Disclosed is an apparatus for producing composite gas used for fabricating nanocomposite materials. The apparatus includes a pressure tank having a housing, which has an internal space and an upper opening, and a closing cap opening or closing the opening, a carrier mounted below the housing, a gas supply supplying inert gas into the pressure tank, a powder supply mounted to the closing cap to supply nano-powders into the pressurized inert gas tank, an exhaust part discharging the inert gas containing nano-powders supplied into the pressure tank, an upper rotor disposed to the inner side of the closing cap, and a lower fan mounted at a lower portion of the housing.

Abstract: A free-machinable hyper-eutectic Al—Si alloy includes 3.0-5.0 wt % Cu, 13-17 wt % Si, 0.2-0.5 wt % Fe, 2.5-6.0 wt % Bi, 0.005-0.02 wt % P, up to 0.1 wt % Mg, up to 0.1 wt % Ni, up to 0.5 wt% Mn and up to 0.5 wt % total sum of other elements, with the balance of the alloy being Al. The hyper-eutectic Al—Si alloy is advantageous in light of excellent machinability, easy cutting operation, extended lifetime of cutting tools and improved smoothness of cutting faces. In addition, the alloy has excellent elongation ratio and abrasion resistance, while maintaining mechanical properties such as rupture strength, tensile strength, yield strength and hardness which are similar to conventional A390 alloy, and thus can be applied to abrasion resistance-requiring applications, for example, swash plates of compressors for automotive air conditioners, without any surface treatment including anodizing or Sn plating.

Abstract: A free-machinable eutectic Al—Si alloy including 3.0-5.0 wt % Cu, 10.0-13.0 wt % Si, 0.2-0.5 wt % Fe, 2.5-5.0 wt % Bi, 0.1-0.3 wt % Sb, up to 0.1 wt % Mg, up to 0.1 wt % Ni and up to 0.5 wt % total sum of other elements, with the balance of the alloy being Al. The eutectic Al—Si alloy is advantageous in light of excellent machinability, easy cutting operation, extended lifetime of cutting tools and improved smoothness of cutting faces. In addition, the alloy has an excellent elongation ratio and abrasion resistance and good formability, while maintaining mechanical properties such as impact strength, tensile strength, yield strength and hardness which can be applied to compressor piston for air conditioner in motorcars, and thus can be applied to abrasion resistance-requiring applications, for example, piston of compressors for automotive air conditioners, without any surface treatment including anodizing or Sn plating.