Method of forming a sintered powdered metal piston ring

Claim 1

A PROCESS OF FORMING A POWDERED METAL PISTON RING CHARACTERIZED BY HIGH SCORE AND WEAR RESISTANCE, SAID PROCESS COMPRISING FORMING A POWDERED FERROUS BASE MIXTURE CONSISTING ESSENTIALLY OF APPROXIMATELY 0.5% TO 15% BY WEIGHT OF A PULVERIZED TITANIUM-ALUMINUM ALLOY HAVING A TITANIUM CONTENT BETWEEN 30% AND 90% AND THE BALANCE SUBSTANTIALLY ALL A MEMBER SELECTED FROM THE GROUP CONSISTING OF IRON AND STEEL, BRIQUETTING SAID MIXTURE AT A PRESSURE OF ABOUT 30,000 TO 90,000 POUNDS PER SQUARE INCH IN AN ANNULAR DIE, SINTERING SAID BRIQUETTE AT A TEMPERATURE BETWEEN APPROXIMATELY 1900* F. AND 2250* F. FOR ABOUT 15 MINUETS TO TWO HOURS, THEREAFTER SIZING THE FORMED PISTON RING BLACK AT ROOM TEMPERATURE AT A PRESSURE OF ABOUT 40,000 TO 150,000 POUNDS PER SQUARE INCH IN A DIE WHICH IS SHAPED TO THE CONTOUR OF THE RING IN ITS FREE AND OPEN POSITION, AND SUBSEQUENTLY TEMPERING SAID BLANK FOR APPROXIMATELY 30 TO 60 MINUETS AT A TEMPERATURE BETWEEN 800* F. AND 1100* F.