Metallurgical and Materials Transactions A

, Volume 15, Issue 6, pp 1103–1110 | Cite as

Retarded grain boundary mobility in activated sintered molybdenum

  • P. E. Zovas
  • R. M. German
Symposium on Activated and Liquid Phase of Refractory Metals and Their Compounds


Rapid grain growth accompanies the enhanced sintering of molybdenum treated with nickel additions. Grain growth is detrimental to sintering kinetics and mechanical properties. A sintering model is developed to illustrate that reducing grain boundary mobility is a means to increase the densification rate. A fine silica dispersion is added to molybdenum powder which is activated by the addition of nickel. This powder exhibits a long term sintering benefit due to retarded grain growth which is attributed to dispersoid drag effects on grain boundaries. These experimental powders are further analyzed through precision dilatometry, showing a characteristic shift in shrinkage rate during constant heating rate experiments. The shrinkage rate of molybdenum is increased by a factor of 10 at 1000°C when activated with 0.37 pct Ni. The shrinkage rate of nickel activated molybdenum is further increased by 67 pct with 1400 ppm silica dispersed at the interparticle grain boundaries.


Metallurgical Transaction Shrinkage Rate Boundary Mobility Densification Rate Molybdenum Powder 
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Copyright information

© The Metallurgical of Society of AIME 1984

Authors and Affiliations

  • P. E. Zovas
    • 1
  • R. M. German
    • 2
  1. 1.Engineering Staff, Sikorsky AircraftStratford
  2. 2.Materials Engineering DepartmentRensselaer Polytechnic InstituteTroy

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