Development of unique cross-lamellar microstructure, resulting in the drastic increase in fracture toughness in Cr/Ir-codoped (Mo0.85Nb0.15)Si2 crystals. (1st April 2017)

• Record Type: Journal Article
• Authors: Hagihara, Koji; Ikenishi, Takaaki; Nakano, Takayoshi
• Is Part Of: Scripta materialia. Number 131(2017)
• Page Start: 19
• Page End: 23
• Publication Date: 2017-04-01
• Subjects: Transition-metal silicides -- Lamella -- Fracture toughness -- Microstructure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2016.12.029
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: We first found a development of unique "cross-lamellar microstructure" in the (Mo0.85 Nb0.15 )Si2 C40/C11b two-phase crystals which is a promising ultrahigh-temperature structural material, via the codoping of Cr and Ir. In the cross-lamellar microstructure, rod-like C11b -phase grains that extend along a direction perpendicular to the lamellar interface develop in addition to fine lamellae. The fine lamellar microstructure increases in the frequency of delamination for crack-tip blunting, and in addition the rod-like C11b -phase grains enhances its effectiveness by inducing the shear-ligament-like toughening. As a result, the drastic increase in fracture toughness, which was never accomplished until now, could be first achieved. Graphical abstract: