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Spray forming of Al/SiC metal matrix composites
Author(s) -
GRANT P. S.,
CHANG I. T. H.,
CANTOR B.
Publication year - 1995
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1995.tb03565.x
Subject(s) - materials science , microstructure , spray forming , dislocation , precipitation , deposition (geology) , composite material , substrate (aquarium) , metallurgy , grain boundary , matrix (chemical analysis) , composite number , metal , paleontology , physics , oceanography , sediment , meteorology , biology , geology
Summary This paper describes the as‐sprayed microstructure of a model Al‐4wt%Cu/SiC particulate (Al4Cu/SiC p ) metal matrix composite (MMC) manufactured by spray forming, and the relationship between microstructure and solidification conditions during manufacture. Injection of SiC p into the melt atomization region during the spray forming of Al4Cu results in significant SiC p incorporation into molten droplets during atomization, and relatively little incorporation during flight to the substrate and at deposition. SiC p clustering is evident in the Al4Cu droplets and results in clustering in the as‐sprayed MMC deposit. Matrix dislocation and precipitation microstructures are dependent upon local solidification conditions during spray forming. Increased dislocation density and increased quantity of fine‐scale θ′‐Al 2 Cu precipitation is found in the α‐Al(Cu) matrix where local deposit cooling rates are high, i.e. in the vicinity of the substrate/deposit interface and when increased spray distances are used in manufacture. Lower dislocation density and increased quantity of grain‐boundary θ‐Al 2 Cu is found where deposit cooling rates are relatively low, i.e. distant from the substrate/deposit interface and at decreased spray distances. In all cases, dislocation densities are higher in α‐Al(Cu)/SiC p interfacial regions than in the α‐Al(Cu) matrix. There is no evidence of α‐Al(Cu)/SiC p interfacial reaction in the as‐sprayed condition indicating that cooling rates during spray forming are sufficiently rapid to prevent reaction.