%0 Journal Article
%4 sid.inpe.br/mtc-m21c/2020/
%2 sid.inpe.br/mtc-m21c/2020/
%@issn 1687-8434
%T The Influence of high-temperature nitrogen plasma-based ion implantation on niobium creep behavior
%D 2020
%9 journal article
%A Oliveira, Aline Capella de,
%A Reis, Joares Lidovino dos,
%A Oliveira, Rogério de Moraes,
%A Reis, Danieli Aparecida Pereira,
%@affiliation Universidade Federal de São Paulo (UNIFESP)
%@affiliation Universidade Federal de São Paulo (UNIFESP)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Universidade Federal de São Paulo (UNIFESP)
%@electronicmailaddress aline.capella@unifesp.br
%@electronicmailaddress rogerio.oliveira@inpe.br
%B Advances in Materials Science and Engineering
%V 2020
%P e9745082
%X Niobium has been considered for applications in the aerospace sector, but its use at high temperatures is restricted, due to the great affinity of refractory metals with oxygen, which results in the formation of oxide layers and a decrease in their mechanical resistances. In the present work, Nb samples were submitted to High-Temperature Nitrogen Plasma-Based Ion Implantation (HT-NPBII). The process runs at a working pressure between 3 and 4 mbar and negative high voltage pulses of 7 kV/30 mu s/300 Hz were applied to samples heated to 1000 degrees C, at treatment times of 1 h, 4 h, and 8 h, respectively. Microstructural and mechanical characterizations of the treated samples revealed the formation of a layer of Nb2N, with 3.0 mu m thickness and increase in the surface hardness from 225 HV for the untreated material up to about 2498 HV, for samples treated during 8 h. Creep tests were performed at 500 degrees C and with loads varying from 25 to 40 MPa. Results indicated a decrease in the secondary creep rate for treated specimens when compared to the untreated ones. This behavior can be attributed to the formation of a nitride layer on the surface of Nb that acts as barrier to avoid the oxygen diffusion into the material under high temperature conditions.
%@language en
%3 oliveira_influence.pdf