Preparation and Triborogical Characterization of ZrO₂(3Y)+20wt%Al₂O₃/SUS410L Stainless Steel Composite Functionally Graded Material Fabricated by Spark Plasma Sintering Method

Abstract

Composite Functionally Graded Materials of ZrO₂(3Y)+20wt%Al₂O₃/SUS410L Stainless steel were prepared using Spark Plasma Sintering method. Mixed powders for inter layers were made of SUS410L and ZrO₂(3Y)of 90, 80, 70, 60, 50 and 30 vol%. Three kinds of ceramic 100% layer were provided. Each of the ceramic 100% top coat layers were A=ZrO₂(3Y), B=ZrO₂(2Y)+20vol%aAl₂O₃ and C=ZrO₂(3Y)+20wt%Al₂O₃. These were stacked and laminated and sintered for 10 min. The sintering temperature of the ZrO₂ layer was ca. 1473K-1643K and that of the SUS410L layar was ca. 1273K-1373K. The FGM containing SUS410L was fabricated dense and free from pores or cracks. The stress due to the thermal expansion mismatch was delocalized by the graded structures and no crack appeared. However, the compressive residual stress acted to decrease the fracture toughness of the ZrO₂(3Y) layer. The ZrO₂+20wt%Al₂O₃ composite layer achieved higher fracture toughness and higher wear resistance than the ZrO₂(3Y) layer. Triborogical characterization is also investigated.