The Influence of Laser Nitriding on Creep Behavior of Ti-4Al-4V Alloy with Widmanstatten Microstructure

Author(s)

Narciso da Silva Briguente, Luciana Aparecida ^[1] ; Onoro, Javier ^[2] ; Briguente, Flavio Perpetuo ^[3] ; Resende, Fabricia Assis ^[1] ; dos Reis, Joares Lidovino ^{[1, 4]} ; Pereira Reis, Danieli Aparecida ^{[1, 5]} ; de Oliveira, Aline Capella ^[1]

Affiliation

^[1] Univ Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, Rua Talim 330, BR-12231280 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Politecn Madrid, ETSI Ind, C Jose Gutierrez Abascal 2, E-28006 Madrid - Spain

^[3] Int Soc Automat Secao Vale Paraiba R Argemiro San, 152 Chacaras Selles, BR-12505473 Guaratingueta, SP - Brazil

^[4] Fac Tecnol Prof Jessen Vidal, Av Cesare Mansueto Giulio Lattes 1350, BR-12247014 Sao Jose Dos Campos, SP - Brazil

^[5] Inst Tecnol Aeronaut, DCTA, Dept Mat & Proc, BR-12228900 Sao Jose Dos Campos - Brazil

• Document type: Journal article
• Source: METALS; v. 9, n. 2 FEB 2019.
• Web of Science Citations: 2

Abstract

Ti-6Al-4V alloy has been considered in applications of aeronautical and aerospace industries, due to its properties such as high specific resistance, good creep resistance and metallurgical stability. However, its use in applications for high temperatures is restricted due to its great affinity with the oxygen, which results in the formation of oxide layers and limits its mechanical resistance at these conditions. Thus, specific treatments have been employed in the material to work as surface barriers to avoid the oxygen diffusion in the alloy under high temperature conditions. One surface treatment that can be used is laser nitriding. In the present work, the surface of Ti-6Al-4V alloy with Widmanstatten microstructure was nitrided by applying Nd:YAG laser focal with 0.6 mm diameter, at laser power of 700, 750 and 800 W, process speed of 100 mm/s and 20 L/min of N-2 flow. Creep tests were performed at constant load at 600 degrees C and 125 MPa, to verify the influence of treatment on the Ti-6Al-4V alloy. Results have indicated a lower stationary creep rate for the titanium alloy with Widmanstatten laser-nitrided structure when compared to the non-nitriding material. Besides that, the surface hardness increased from 368 HV of base material to 1000 HV after laser nitriding. (AU)

• FAPESP's process: 15/18235-0 - Formation and growth of intermetallics at the interface between Al-Si and Ti-6Al-4V
• Grantee: Aline Gonçalves Capella
• Support Opportunities: Regular Research Grants