SINTERING STRESSES MEASUREMENT : EQUIPMENT AND METHOD

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SINTERING STRESSES MEASUREMENT EQUIPMENT AND
METHOD Claire Theron, W. Roger Cannon and Vimal
K. Pujari Ceramic and Materials Engineering,
Rutgers University, Piscataway, NJ Saint Gobain,
RD Center, Northboro, MA

• Objectives
• Determine the sintering stress of silicon nitride
• Apply finite element model to predict sintering
  shrinkage and distortion

Sintering stress measurement
The sintering stress, ?, is the driving force
for sintering and is related to surface and grain
boundary energies and geometry. The sintering
stress can also be viewed as the tensile
hydrostatic stress necessary to stop sintering.

• Measurement of the sintering stresses parameters
• Measurement of the axial displacement digital
  LVDT
• Measurement of the diameter shrinkage Laser
  extensometer.
• Laser extensometer moves vertically by computer
  control to measure distortion.

acquisition system
compressive stress applied
The densification rate is determined as a
function of the compressive sinter-forging stress
applied to the sample Then extrapolation of
the linear densification rate with compressive
stress onto the tensile side to zero
densification rate, gives the hydrostatic
stress necessary to stop the sintering
process. The system makes density measurements
in situ during sinter forging.for determination
of sintering stresses at different stage of
the sintering process.
sample
inside of the Centorr furnace