Dy. Ding et al., Interfacial reactions and mechanical properties of 6061A1 matrix composites reinforced with alumina-coated Al18B4O33 whiskers, MATER LETT, 45(1), 2000, pp. 6-11
Sol-gel gamma-Al2O3 and alpha-Al2O3 ceramic coatings were deposited onto su
rfaces of aluminum borate whiskers to control the spinel reactions between
whiskers and matrix alloys. Interface observations, tensile experiments and
hardness measurements of the composites were conducted to evaluate the coa
ting effect. By comparison with gamma-Al2O3 coating, the alpha-Al2O3 coatin
g was found to be more effective in controlling the interfacial reactions,
and it helped to enhance the elastic modulus of the composite. The introduc
tion of alumina coatings to the composite postponed the peak-aging process,
due to a smaller depletion of magnesium in the matrix of the coated compos
ites. (C) 2000 Elsevier Science B.V. All rights reserved.