Open AccessStructure and properties of invar alloys for MIM technologies
Author(s) -
S. N. Kulkov,
E. V. Abdulmenova,
В. С. Шадрин,
Andrey Leonov,
R. V. Levkov
Publication year - 2019
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/696/1/012005
Subject(s) - materials science , invar , sintering , lattice constant , metallurgy , grain size , porosity , alloy , phase (matter) , indentation hardness , lattice (music) , analytical chemistry (journal) , composite material , microstructure , diffraction , chromatography , chemistry , physics , organic chemistry , optics , acoustics
The paper studied Fe-Ni alloys obtained by sintering from mixtures of powders. Powders with 30-40 wt. Ni were mixed with paraffin and wax binder and then pressed and sintered at 1300 °C during 1 hour. It has been shown that the face centered cubic lattice (γ-phase) and body centered cubic lattice (α-phase) are formed after sintering of powders mixture. The content of the α-phase decreases from 37 % to 2 % with increase of Ni concentration from 30 to 35 wt. % Ni in powders mixture. The average grain size of the γ-phase decreases from 26.5±12.3 μm to 18.3±9.1 μm, and porosity of samples increases from 13±1.4 % to 18.4±1.1 %.The lattice parameter of the γ-phase increases from 3.5849·10 −10 m to 3.597·10 −10 m and it corresponds to well-known invar alloys. The maximum value of the microhardness of sintered samples is 1.04±0.07 GPa. Thus, alloys obtained by sintering of Fe and Ni powder mixtures has an invar properties typical of cast alloys.