Metal-oxide gradient ceramic bodies

Claim 1

PROCESS FOR THE MANUFACTURE OF GRADED CERMETS OF METAL AND OXIDE COMPONENTS CHANGING FROM A HIGH PROPORTION OF METAL BY VOLUME AT ONE REGION TO A HIGH PROPORTION OF OXIDE BY VOLUME AT AN OPPOSITE REGION, COMPRISING PROVIDING A SERIES OF AT LEAST 5 UP TO ABOUT 11 POWDER BATCHES OF VERY FINELY DIVIDED AND INTIMATELY MIXED METAL AND METALLIC OXIDE COMPONENTS OF GRADUALLY INCREASING OXIDE CONTENT FROM THE FIRST BATCH UP TO THE LAST BATCH, THE LAST BATCH CONSISTING SUBSTANTIALLY ENTIRELY OF THE METALLIC OXIDE, THE METAL/METAL OXIDE RATIOS IN SAID SERIES OF BATCHES VARYING APPROXIMATELY DIRECTLY (AS A STRAIGHT LINE) BY WEIGHT RATHER THAN BY VOLUME, COMBINING SUBSTANTIALLY EQUAL LAYERS OF SAID SERIES OF ORDERED BATCHES IN SUFFICIENT AMOUNT TO PROVIDE LAYERS OF AT LEAST ABOUT 1 MM. PER BATCH IN THICKNESS WHEN COMPRESSED, COMPRESSING SAID LAYERS TO FORM AN ARTICLE AND SINTERING THE RESULTANT ARTICLE.