author = "Oliveira, Aline Capella de and Oliveira, Rogerio de Moraes and 
                         Reis, D. A. P. and Carreri, Felipe de Campos",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Federal 
                         de S{\~a}o Paulo (UNIFESP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Effect of nitrogen high temperature plasma based ion implantation 
                         on the creep behavior of Ti-6Al-4V alloy",
              journal = "Applied Surface Science",
                 year = "2014",
               volume = "311",
                pages = "239--244",
             keywords = "Aluminum, Ion implantation, Nitrogen, Titanium alloys, Constant 
                         load creep tests, Creep behaviors, High-temperature plasmas, 
                         Micro-structural characterization, Plasma-based ion implantation, 
                         Simultaneous formation, Steady state creep rate, Ti-6Al-4V alloy, 
             abstract = "Nitrogen high temperature plasma based ion implantation (HTPBII) 
                         performed on Ti-6Al-4V significantly improved the creep behavior 
                         of the alloy. Treatments were performed for 1 h at a working 
                         pressure of 4 mbar and negative high voltage pulses of 7.5 kV, 30 
                         s and 500 Hz were applied on the specimens heated at 800 C and 
                         900 C, respectively. Microstructural characterization of the 
                         treated samples revealed the formation of nitrided layers, with 
                         simultaneous formation of TiN and Ti2N. The most intense peaks of 
                         these compounds were obtained at higher treatment temperature, 
                         probably due to the diffusion of nitrogen into titanium. The 
                         presence of nitrides caused surface hardening up to three times 
                         higher in comparison with untreated alloy. Constant load creep 
                         tests were conducted on a standard creep machine in air 
                         atmosphere, at stress level of 319 MPa at 600 C. Significant 
                         reductions of the steady-state creep rates () were measured for 
                         martensitic Ti-6Al-4V treated by nitrogen HTPBII, reaching minimum 
                         creep rates of 0.0318 h-1 in comparison with 0.1938 h-1 for 
                         untreated sample. The improvement of the creep resistance seems to 
                         be associated with the formation of a thick nitrided layer, which 
                         acts as a barrier to oxygen diffusion into the material. In 
                         addition, the increase of the grain size generated by the heating 
                         of the substrate during the treatment can affect some creep 
                         mechanisms, leading to a significant reduction of .  2014 
                         Elsevier B.V.",
                  doi = "10.1016/j.apsusc.2014.05.047",
                  url = "http://dx.doi.org/10.1016/j.apsusc.2014.05.047",
                 issn = "0169-4332",
                label = "scopus 2014-11 OliveiraOlivReisCarr:2014:EfNiHi",
             language = "en",
        urlaccessdate = "28 nov. 2020"