Detailed surface analyses and improved mechanical and tribological properties of niobium treated by high temperature nitrogen plasma based ion implantation

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 μs/300 Hz were applied to samples heated to 1000°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 μm 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°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.

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Mechanical and tribological properties of AISI 304 stainless steel nitrided by glow discharge compared to ion implantation and plasma immersion ion implantation

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/j.nimb.2007.01.266 ◽

2007 ◽

Vol 257 (1-2) ◽

pp. 732-736 ◽

Cited By ~ 52

Author(s):

C.E. Foerster ◽

F.C. Serbena ◽

S.L.R. da Silva ◽

C.M. Lepienski ◽

C.J. de M. Siqueira ◽

...

Keyword(s):

Stainless Steel ◽

Glow Discharge ◽

Ion Implantation ◽

Tribological Properties ◽

304 Stainless Steel ◽

Aisi 304 Stainless Steel ◽

Aisi 304 ◽

Mechanical And Tribological Properties ◽

Plasma Immersion Ion Implantation

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Improvements of tribological properties of CrNiMo and CrCoMo alloys by nitrogen plasma immersion ion implantation

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2005.01.072 ◽

2005 ◽

Vol 200 (1-4) ◽

pp. 594-597 ◽

Cited By ~ 2

Author(s):

M. Ueda ◽

L.A. Berni ◽

R.M. Castro ◽

H. Reuther ◽

C.M. Lepienski ◽

...

Keyword(s):

Ion Implantation ◽

Tribological Properties ◽

Nitrogen Plasma ◽

Plasma Immersion Ion Implantation

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The Surface Treatment of Niobium Superconducting Reentrant Cavities by Means of High Temperature Nitrogen Plasma Based Ion Implantation

Materials Research ◽

10.1590/1980-5373-mr-2019-0277 ◽

2019 ◽

Vol 22 (6) ◽

Author(s):

Rogério Moraes Oliveira ◽

Odylio Denys Aguiar ◽

Michel Felipe Lima de Araujo ◽

Matheus M. N. F. Silva ◽

Carina B. Mello ◽

...

Keyword(s):

High Temperature ◽

Ion Implantation ◽

Surface Treatment ◽

Nitrogen Plasma

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Einfluss einer chemischen Kopplung von strahlenmodifiziertem PTFE mit PA46 auf mechanische Eigenschaften und das Reib- und Verschleißverhalten

Tribologie und Schmierungstechnik ◽

10.24053/tus-2021-0011 ◽

2021 ◽

Vol 68 (2) ◽

Author(s):

Lionel Simo Kamga ◽

Thanh-Duong Nguyen ◽

Thomas Schmidt ◽

Michaela Gedan-Smolka ◽

Stefan Emrich ◽

...

Keyword(s):

High Temperature ◽

Coefficient Of Friction ◽

Tribological Properties ◽

Reactive Extrusion ◽

Hardened Steel ◽

Peroxy Radicals ◽

Mechanische Eigenschaften ◽

Temperature Resistance ◽

Mechanical And Tribological Properties ◽

Radiation Modification

In dry-lubricated tribological systems, polytetrafluoroethylene (PTFE) or polyamide (PA) are often used as dry lubricants. PTFE is characterized by a low coefficient of friction and a high wear rate when sliding against steel and a high temperature resistance. In contrast to PTFE, PA has a higher coefficient of friction when sliding against steel. The radiation modification of PTFE in air generates functional groups (-COF and -COOH) and persistent perfluoroalkyl (peroxy) radicals, which, when chemically coupled with suitable polymers, lead to compounds with improved tribological properties. In this paper, the mechanical and tribological properties of PA46-PTFE-cb (chemical bonded) that were kept by reactive extrusion were characterized. For this purpose, Block-on-ring tests were performed using hardened steel discs made of 16MnCr5 as counterparts.

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