Method of making a compound valve seat

A method of producing a compound sintered article using a press-molding machine provided with a compression space defined by a die, a core rod, an upper punch and a lower punch, and including means for feeding different kinds of powder, in which at least two different powders are charged into the compression space, compressively molded, and then sintered, comprising;

• moving said lower punch relatively downwardly to form a first space, and advancing first feeding means to charge a first powder into said first space;
• moving said upper punch provided with a shaped protrusion at its inner circumference relatively downwardly to compress said first powder to form of preparatory green compact;
• moving said upper punch upwardly, and at the same time causing said lower punch to move relatively to said die so as to dispose the upper surface of said preparatory green compact at a predetermined position, and advancing second feeding means to charge a second powder into a space formed above said preparatory green compact;
• moving said upper punch downwardly to compressively integrally mold said second powder together with said preparatory green compact to form a final green compact;
• removing said final green compact;
• and
• sintering said final green compact.