Effect of nitrogen implantation on fatigue crack initiation in ferritic Fe-24Cr-4Al alloy

Journal Article · Wed Feb 15 04:00:00 EST 1995 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(95)90833-6· OSTI ID:6873189

Tjong, S C; Zhu, S M ^[1]

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1. City Polytechnic of Hong Kong, Kowloon (Hong Kong). Dept. of Physics and Materials Science

Nitrogen implantation in a ferritic Fe-24Cr-4Al alloy results in cyclic hardening behavior and a slight improvement in fatigue life. Optical and SEM observations reveal that the slip bands are more homogeneous in the implanted alloy than those of the un-implanted specimen and the density of slip bands is significantly lower at the surface of the implanted alloy. For the un-implanted alloy, impingement of persistent slip bands (PSBs) at the free surface leads to the initiation of intergranular cracks. However, the emergence of PSBs at the free surface is retarded in the implanted alloy due to the interaction between PSBs and nitrides of the implanted layer. The surface cracks exhibit a brittle appearance for the ion beam modified specimen.

• OSTI ID: 6873189
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 32:4; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
ALUMINIUM ALLOYS
CARBON ADDITIONS
CHROMIUM ALLOYS
ELECTRON MICROSCOPY
ELEMENTS
FATIGUE
ION IMPLANTATION
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
MICROSCOPY
NITROGEN
NONMETALS
OPTICAL MICROSCOPY
SAMPLE PREPARATION
SCANNING ELECTRON MICROSCOPY
SLIP