Investigation of a High-Temperature Nb-Based Composite Material Mechanically Doped with Si

—The influence of Si and uncontrolled interstitial impurities (oxygen and carbon) in trace amounts on the strength characteristics of a high-temperature composite material (HCM) based on Nb obtained by the powder metallurgy technique has been studied. It has been established that the bending strengt...

Full description

Saved in:
Bibliographic Details
Published in:Inorganic materials : applied research 2019, Vol.10 (5), p.1033-1038
Main Authors: Shchetanov, B. V., Graschenkov, D. V., Efimochkin, I. U., Paegle, S. V., Dvoretskov, R. M.
Format: Article
Language:English
Subjects:
Alloy powders
Bend strength
Chemistry
Chemistry and Materials Science
Cold treatment
Cold working
Composite materials
Dislocations
Dispersion hardening
High temperature
Homogenization
Industrial Chemistry/Chemical Engineering
Inorganic Chemistry
Interstitial impurities
Materials for Aerospace Technology
Materials Science
Mechanical alloying
Metallurgical analysis
Niobium carbide
Planetary mills
Porosity
Powder metallurgy
Silicides
Silicon
Ultrafines
Work hardening
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:—The influence of Si and uncontrolled interstitial impurities (oxygen and carbon) in trace amounts on the strength characteristics of a high-temperature composite material (HCM) based on Nb obtained by the powder metallurgy technique has been studied. It has been established that the bending strength of specimens manufactured by mechanical homogenization and mechanical alloying exceeds the strength of a material obtained from an original niobium powder by a factor of 3–4.5, with the main contribution to the increase in strength being made by mechanical homogenization of the original niobium. Optimal HCM properties were obtained during alloying of the Nb powder in a planetary mill with 1 wt % Si and uncontrolled impurities (O and C). An assumption was put forward about the mechanisms of HCM hardening: when using homogenized Nb (without silicon), the hardening proceeds by two mechanisms, both by the cold-work hardening of niobium powder (dislocation mechanism) and by the uncontrolled impurities (O and C) that form ultrafine oxides and niobium carbides (dispersion hardening); after Si introduction, an additional dispersion hardening with niobium silicides takes place. The authors do not exclude the effect of porosity on the strength of the material.
ISSN:2075-1133
2075-115X
DOI:10.1134/S2075113319050290