TY - JOUR
T1 - Processing and composition effects on the fracture behavior of spray-formed 7XXX series Al alloys
AU - Sharma, M. M.
AU - Ziemian, C. W.
AU - Eden, T. J.
N1 - Funding Information:
The authors would like to thank Naval Sea Systems Command for the financial support of this research under contract No. N00039-97-D-0042, Delivery Order Nos. 0214 and 0215
PY - 2010/12
Y1 - 2010/12
N2 - The fracture properties of high-strength spray-formed Al alloys were investigated, with consideration of the effects of elemental additions such as zinc, manganese, and chromium and the influence of the addition of SiC particulate. Fracture resistance values between 13.6 and 25.6 MPa (m) 1/2 were obtained for the monolithic alloys in the T6 and T7 conditions, respectively. The alloys with SiC particulate compared well and achieved fracture resistance values between 18.7 and 25.6 MPa (m) 1/2. The spray-formed materials exhibited a loss in fracture resistance (K I) compared to ingot metallurgy 7075 alloys but had an improved performance compared to high-solute powder metallurgy alloys of similar composition. Characterization of the fracture surfaces indicated a predominantly intergranular decohesion, possibly facilitated by the presence of incoherent particles at the grain boundary regions and by the large strength differential between the matrix and precipitate zone. It is believed that at the slip band-grain boundary intersection, particularly in the presence of large dispersoids and/or inclusions, microvoid nucleation would be significantly enhanced. Differences in fracture surfaces between the alloys in the T6 and T7 condition were observed and are attributed to inhomogeneous slip distribution, which results in strain localization at grain boundaries. The best overall combination of fracture resistance properties were obtained for alloys with minimum amounts of chromium and manganese additions.
AB - The fracture properties of high-strength spray-formed Al alloys were investigated, with consideration of the effects of elemental additions such as zinc, manganese, and chromium and the influence of the addition of SiC particulate. Fracture resistance values between 13.6 and 25.6 MPa (m) 1/2 were obtained for the monolithic alloys in the T6 and T7 conditions, respectively. The alloys with SiC particulate compared well and achieved fracture resistance values between 18.7 and 25.6 MPa (m) 1/2. The spray-formed materials exhibited a loss in fracture resistance (K I) compared to ingot metallurgy 7075 alloys but had an improved performance compared to high-solute powder metallurgy alloys of similar composition. Characterization of the fracture surfaces indicated a predominantly intergranular decohesion, possibly facilitated by the presence of incoherent particles at the grain boundary regions and by the large strength differential between the matrix and precipitate zone. It is believed that at the slip band-grain boundary intersection, particularly in the presence of large dispersoids and/or inclusions, microvoid nucleation would be significantly enhanced. Differences in fracture surfaces between the alloys in the T6 and T7 condition were observed and are attributed to inhomogeneous slip distribution, which results in strain localization at grain boundaries. The best overall combination of fracture resistance properties were obtained for alloys with minimum amounts of chromium and manganese additions.
UR - https://www.scopus.com/pages/publications/78650787568
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U2 - 10.1007/s11665-010-9624-2
DO - 10.1007/s11665-010-9624-2
M3 - Article
AN - SCOPUS:78650787568
SN - 1059-9495
VL - 19
SP - 1344
EP - 1351
JO - Journal of Materials Engineering and Performance
JF - Journal of Materials Engineering and Performance
IS - 9
ER -