Open AccessOptimization of high pressure torsion processing for fabrication of the Al-Nb hybrid system
Author(s) -
G. R. Khalikova,
Г. Ф. Корзникова,
К. С. Назаров,
Р. Х. Хисамов,
С. Н. Сергеев,
R. U. Shayakhmetov,
R. R. Mulyukov
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1008/1/012021
Subject(s) - materials science , niobium , composite number , aluminium , intermetallic , composite material , indentation hardness , fabrication , torsion (gastropod) , deformation (meteorology) , metallurgy , microstructure , medicine , alternative medicine , surgery , alloy , pathology
A hybrid composite material fabricated from the Al-Nb system using high-pressure torsion (HPT) up to 30 turns has been studied in the present work. To fabricate the composite, deformation of a three-layer Al-Nb-Al package was carried out at room temperature on Bridgman anvils with grooves under a pressure of 5 GPa at N=10, 25 and 30 revolutions, at a strain rate of ω =1 and 2 rpm. Initial disc diameters from pure metals and HPT conditions were experimentally optimized to obtain monolithic and defect-free composite samples. The most intensive fragmentation and stirring of niobium in the aluminium matrix was observed if diameter of aluminium discs was 10 mm and deformation conditions N=25 and 30 revolutions and ω =2 rpm were applied. Three microstructural zones were observed after HPT under optimal conditions: the central zone with wide curved layers of niobium in aluminium, the mid-radius zone with finely dispersed layered structure, and periphery with a uniform distribution of niobium in the aluminium matrix. It was shown that HPT led to occurrence of strain-induced ageing resulting in formation of the intermetallic Al 3 Nb phase. The microhardness measured along the diameter of the obtained composite materials changed nonmonotonically depending on the produced structure (microstructural zone).