Development of novel melt spinning based processing route for oxide dispersion strengthened steels
journal contributionposted on 24.11.2017, 15:49 by Zuliang Hong, Alasdair P. Morrison, Hongtao ZhangHongtao Zhang, Steve G. Roberts, Patrick S. Grant
Melt spinning of an Fe-5Y and Fe-1Y-1Ti (wt%) alloys produced a relatively uniform spatial distribution of Y and Ti in solid solution and ribbons with consistent yield (> 60% by weight), fast processing time (< 10 s), good scalability (up to > 100 g feedstock material) and repeatability. Heat treatment in the presence of Fe2O3 as an oxygen source (Rhines pack method) at 973 K validated the potential of forming < 20 nm Yrich oxides in the 1 Fe-5Y ribbons. Pulverized Fe-1Y-1Y ribbons were consolidated to bulk using the field assisted sintering technique (FAST) incorporating nano-sized Fe3O4 powder as the oxygen source. After FAST at 1273 K, 50 MPa and 30 min a comparatively high number density of sub-micron Y and/or Ti-rich oxides were developed. Further formation of fine-scale oxides took place during post-FAST annealing, resulting in an approximate 20% increase in hardness at temperatures below 573 K, but with a reduced hardening effect above 673 K due to a small fraction of persistent porosity and mechanically weak prior ribbon boundaries that were decorated with Ti-rich oxides
UK Engineering and Physical Sciences Research Council provided financial support through grant award EP/P001645/1.
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