The Relationship Between Surface Area and Density in the Second-Stage Sintering of Metals

  • R. T. DeHoff
  • R. A. Rummel
  • H. P. LaBuff
  • F. N. Rhines


Careful quantitative metallographic analysis has shown that surface area and density are linearly related during second-stage sintering of a wide range of size fractions of metal powders. The slope of the line is determined by the coarseness of the pore network and is simply related to its topology. The topology of the pore network is established by the stacking of the unsintered powder, as modified during the passage of the structure through first-stage sintering. Changes in the initial topology of the system may be affected by pre-compaction or the production of porosity internal to the particles, which increase the connectivity of the system and produce a finer structure, and by exaggerated surface rounding, which decreases connectivity, yielding a coarser pore network in second-stage sintering. It is shown that the linear relationship between surface area and density requires that the mean pore intercept be constant throughout second-stage sintering. The implications of this requirement are discussed in detail.


Test Line Copper Powder Nickel Powder Sinter Body Interparticle Contact 


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Copyright information

© Metal Powder Industries Federation and The Metallurgical Society of AIME 1966

Authors and Affiliations

  • R. T. DeHoff
    • 1
  • R. A. Rummel
    • 1
  • H. P. LaBuff
    • 1
    • 2
  • F. N. Rhines
    • 1
  1. 1.University of FloridaGainesvilleUSA
  2. 2.General Electric CompanyClydeUSA

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