Y. Choi
,
T.W. Lim
,
S.I. Hong
金属学报(英文版)
Corrosion behavior of heavily drawn bundled Copper-niobium filamentary micro-composite was studied as a function of niobium content to develop the relationshipbetween microstructure and corrosion behavior in aqueous 30% HCl-FeCl3 solution.TEM observation revealed that niobium filaments were distributed regularly in coppermatrix along the sides of a triangular unit cell in the transverse section and more sub-grain boundaries were absorbed at copper/niobium phase boundaries with increasingniobium content. The corrosion potential and rate in aqueous 30% HCl-10% FeCl3 was-680.3mVSHE and 1.179×10-5A/cra2. The corrosion potential and rate decreasedas increasingniobium content and FeCl3. The yield stress can be described as thesum of the substructure strengthening component due to elongated grains, subgrainsand/or cells, the phase boundary strengthening term associated with the Hall-Petchtype interaction between dislocations and phase boundaries and precipitate strength-ening component.
关键词:
Cu-Nb micro-composites
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null
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null
Y. Choi
,
N.I. Baik
,
H.D. Cho
金属学报(英文版)
TiaAl-Nb-Mo composites were prepared by SHS using initial powder mixtures of Ti-Al-Nb-Mo and their corrosion and mechanical properties were studied to develop bio-and environmental materials. The composites reached 99.8% of theoretical densityafter the direct consolidation. The composites shows equiaxed primary α2 in a matrixof fine secondary α2 plates and ordered B2 (B0) forming a basket weave structure.The strain rate sensitivity (m = dlnσr/dlne) at 2% strain is 0.008. Corrosion po-tential and corrosion rate of the composites formed by SHS were -151.5mVSHE and5.72× 10-8A/cm2 for Ti3Al-10Nb-1.5Mo and -138.4m VSHE and 4.12×10-8cm-2 forTi3Al-12Nb-1.5Mo in a 50% NaOH-10%FeCl3 solution, respectively. Corrosion resis-tance decreased with niobium content in the composites and chloride content in theaqueous solution. Selective corrosion of α2 phase in a matrix occurred in the corrosionenvironment which suggests that the corrosion potential and rate changes are relatedto the niobium content and α2 phase in a matrix.
关键词:
Ti3Al alloy
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null
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null
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