TY - JOUR
T1 - Characterization of AISI 4140 borided steels
AU - Campos-Silva, I.
AU - Ortiz-Domínguez, M.
AU - López-Perrusquia, N.
AU - Meneses-Amador, A.
AU - Escobar-Galindo, R.
AU - Martínez-Trinidad, J.
PY - 2010/2/1
Y1 - 2010/2/1
N2 - The present study characterizes the surface of AISI 4140 steels exposed to the paste-boriding process. The formation of Fe 2 B hard coatings was obtained in the temperature range 1123-1273 K with different exposure times, using a 4 mm thick layer of boron carbide paste over the material surface. First, the growth kinetics of boride layers at the surface of AISI 4140 steels was evaluated. Second, the presence and distribution of alloying elements on the Fe 2 B phase was measured using the Glow Discharge Optical Emission Spectrometry (GDOES) technique. Further, thermal residual stresses produced on the borided phase were evaluated by X-ray diffraction (XRD) analysis. The fracture toughness of the iron boride layer of the AISI 4140 borided steels was estimated using a Vickers microindentation induced-fracture testing at a constant distance of 25 μm from the surface. The force criterion of fracture toughness was determined from the extent of brittle cracks, both parallel and perpendicular to the surface, originating at the tips of an indenter impression. The fracture toughness values obtained by the Palmqvist crack model are expressed in the form K C (π/2) > K C > K C (0) for the different applied loads and experimental parameters of the boriding process.
AB - The present study characterizes the surface of AISI 4140 steels exposed to the paste-boriding process. The formation of Fe 2 B hard coatings was obtained in the temperature range 1123-1273 K with different exposure times, using a 4 mm thick layer of boron carbide paste over the material surface. First, the growth kinetics of boride layers at the surface of AISI 4140 steels was evaluated. Second, the presence and distribution of alloying elements on the Fe 2 B phase was measured using the Glow Discharge Optical Emission Spectrometry (GDOES) technique. Further, thermal residual stresses produced on the borided phase were evaluated by X-ray diffraction (XRD) analysis. The fracture toughness of the iron boride layer of the AISI 4140 borided steels was estimated using a Vickers microindentation induced-fracture testing at a constant distance of 25 μm from the surface. The force criterion of fracture toughness was determined from the extent of brittle cracks, both parallel and perpendicular to the surface, originating at the tips of an indenter impression. The fracture toughness values obtained by the Palmqvist crack model are expressed in the form K C (π/2) > K C > K C (0) for the different applied loads and experimental parameters of the boriding process.
KW - Boriding
KW - Characterization
KW - Diffusion model
KW - Fracture toughness
KW - Growth kinetics
KW - Hard coatings
KW - Residual stresses
UR - http://www.scopus.com/inward/record.url?scp=74149085011&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2009.10.070
DO - 10.1016/j.apsusc.2009.10.070
M3 - Artículo
SN - 0169-4332
VL - 256
SP - 2372
EP - 2379
JO - Applied Surface Science
JF - Applied Surface Science
IS - 8
ER -