Acta Metallurgica Sinica (English Letters) ›› 2002, Vol. 15 ›› Issue (2): 149-153 .

• Research Articles • Previous Articles     Next Articles

CORROSION AND MECHANICAL PROPERTIES OF Ti3Al-Nb-Mo COMPOSITES FOR BIO- AND ENVIRONMENTAL MATERIALS PREPARED BY SELF-PROPAGATING HIGH TEMPERATURE REACTION

Y. Choi, N.I. Baik, H.D. Cho   

  1. Department of Environmental Engineering,Sunmoon University,#100 Kalsan-Ri,Tangjeoung-Myun,Asan,Chungnam,336-840,Korea
  • Received:2001-07-31 Revised:1900-01-01 Online:2002-04-25 Published:2009-10-10
  • Contact: Y. Choi

Abstract: 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.

Key words: Ti3Al alloy, corrosion, strength, SHS