BARC/PUB/2003/0416

 
 

Laser deposition of compositionally graded titanium-vanadium and titanium-molybdenum alloys

 
     
 
Author(s)

Collins, P. C.; Banerjee, R.; Banerjee, S.; and others
(MG)

Source

Materials Science and Engineering-A, 2003. Vol. 352: pp. 118 -128

ABSTRACT

Compositionally graded binary titanium–vanadium and titanium–molybdenum alloys have been deposited using the laser engineered net-shaping (LENSTM) process. A compositional gradient, from elemental Ti to Ti–25at.% V or Ti–25at.% Mo, has been achieved within a length of ~25 mm. The feedstock used for depositing the graded alloy consists of elemental Ti and V (or Mo) powders. Though the microstructural features across the graded alloy correspond to those typically observed in α/β Ti alloys, the scale of the features is refined in a number of cases. Microhardness measurements across the graded samples exhibit an increase in hardness with increasing alloying content up to a composition of ~12% in case of Ti–xV and up to a composition of ~10% in case of the Ti–xMo alloys. Further increase in the alloying content resulted in a decrease in hardness for both the Ti–xV as well as the Ti–xMo alloys. A notable feature of these graded deposits is the large prior β grain size resulting from the directionally solidified nature of the microstructure. Thus, grains ~10 mm in length grows in a direction perpendicular to the substrate. The ability to achieve such substantial changes in composition across rather limited length makes this process a highly attractive candidate for combinatorial materials science studies.

 
 
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