CLUSTER-PLUS-GLUE-ATOM MODEL AND COMPOSITION DESIGN OF BCC Ti-Mo-Nb-Zr SOLID SOLUTION ALLOYS WITH LOW YOUNG'S MODULUS
Received date: 2010-01-21
Revised date: 2010-06-01
Online published: 2010-09-11
Supported by
Supported by National Natural Science Foundation of China (Nos.50901012 and 50631010) and National Basic Research Program of China (No.2007CB613902)
The composition characteristics of typical bcc β-Ti solid solution alloys with low Young's modulus were analyzed by using the cluster-plus-glue-atom model, in which an alloy structure is dissociated into a cluster part and a glue atom part, i.e. isolated clusters are linked with glue atoms. The cluster here is the nearest neighbor coordination polyhedron with a coordination number of 14 (CN14). It is confirmed that β-Ti solid solution alloys with low Young's moduli satisfy a universal cluster formula [CN14 cluster](glue atom)x given by this model. Alloys, described by cluster formulas [MoTi14]Ti, [MoTi14]Nb, [MoTi14]Nb2 and [Mo(Ti13Zr)]Nb2, Ti-11.8Mo (mass fraction, %), Ti-11.2Mo-10.8Nb, Ti-10.1Mo-19.5Nb and Ti-9.2Zr-9.6Mo-18.7Nb were designed and the alloy rods with diameters of 3 and 6 mm were prepared by copper-mould suction-cast method, respectively. These suction-cast alloys possess monolithic bcc β-Ti structure. The introduction of low-modulus Nb as glue atoms weakens the cluster linking and decreases the Young's modulus. Further substitutions with low-modulus Zr reduces the Young's modulus to 72 GPa in the [Mo(Ti13Zr)]Nb2 alloy. Solution treatment plus subsequent water quenching decreases slightly the Young's moduli of the suction-cast alloys.
MA Ren-Shou , DONG Chen , YU Qing , HAO Zhuan-Pu , REN Meng-Fa , YU Yang-Min . CLUSTER-PLUS-GLUE-ATOM MODEL AND COMPOSITION DESIGN OF BCC Ti-Mo-Nb-Zr SOLID SOLUTION ALLOYS WITH LOW YOUNG'S MODULUS[J]. Acta Metall Sin, 2010 , 46(9) : 1034 -1040 . DOI: 10.3724/SP.J.1037.2010.00039
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