Abstract: A method is provided of producing a hardmetal-bonded metal component with an enhanced bond strength. The method comprises the steps of providing an iron-based metal body, mixing and compressing raw material powder of hardmetal and binder powder containing nickel, silicon and boron into a preform, heating and sintering the preform, and applying heat to the sintered body and the iron-based metal body under a state that the sintered body is brought into contact with the iron-based metal body, to thereby cause the sintered body to be bonded to the iron-based metal body. The sintered body and the iron-based metal body are thermally treated at a temperature of 1,000 to 1,200° C. for 30 or more minutes so that boron present in the sintered body is infiltrated into grain boundaries of the iron-based metal body to form a plurality of boride spikes in a bonding interface.

Abstract: A method is provided of producing a hardmetal-bonded metal component with an enhanced bond strength. The method comprises the steps of providing an iron-based metal body, mixing and compressing raw material powder of hardmetal and binder powder containing nickel, silicon and boron into a preform, heating and sintering the preform, and applying heat to the sintered body and the iron-based metal body under a state that the sintered body is brought into contact with the iron-based metal body, to thereby cause the sintered body to be bonded to the iron-based metal body. The sintered body and the iron-based metal body are thermally treated at a temperature of 1,000 to 1,200° C. for 30 or more minutes so that boron present in the sintered body is infiltrated into grain boundaries of the iron-based metal body to form a plurality of boride spikes in a bonding interface.

Abstract: The invention relates to an apparatus of an exhaust gas recirculation valve for an internal combustion engine for preventing the thermal effect on an intake manifold due to high temperature of recirculated exhaust gas. The apparatus of EGR valve is comprised of an exhaust gas recirculation valve consisting of a body and an adapter having a second flange which causes the body to be attached on a first flange of the intake manifold. A gap of 3 mm to 5 mm separates a first border of the first flange from a second border of the adapter.

Abstract: A method of producing a wear resistant mechanical component is disclosed which enables the crown value of a wear resistant tip to be controlled at one's desire. A component preform is provided by placing the wear resistant tip on a metal body with a brazing material interposed between them. The wear resistant tip has a smaller coefficient of thermal expansion than that of the metal body. The component preform is heated up to a brazing temperature selected from the temperature range between an austenite transformation starting temperature at which the metal body begins to undergo austenitic transformation and an austenitic transformation ending temperature at which the metal body terminates the austenitic transformation. The heated component preform is cooled down to the normal temperature so that the wear resistant tip is deformed into a crown shape having a crown value corresponding to the brazing temperature.