Abstract
A master alloy ingot of Nb-Cr based multi-element alloy has been prepared by vacuum non-consumable arc-melting, and then vacuum consumable arc-melting and heat treated at 1450°C for 24 h and 1000°C for 24 h, then oxidized at 950°C in air for different times for the heat treated samples. The room temperature fracture toughness is measured by a three-point bending method. It has been found that the Nb based solid solution (Nbss) transforms from dendrites into equiaxed grains, and the Cr2(Nb, Ti, Hf) Leves phase transforms from blocks into rods with more smooth boundaries after heat treatment. The arc-melted samples rupture in a brittle cleavage mode, but the heat treated samples rupture in a quasi-cleavage mode. The scale is composed of CrNbO4, HfO2, TiO2, CrNb11O29 and Ti2Nb10O29 phases when the samples are oxidized at 950°C for different times.
| Original language | English |
|---|---|
| Pages (from-to) | 984-988 |
| Number of pages | 5 |
| Journal | Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering |
| Volume | 37 |
| Issue number | 6 |
| State | Published - Jun 2008 |
Keywords
- Arc-melting, heat treatment
- High temperature oxidation
- Nb-Cr based multi-element alloy
- Room temperature fracture toughness