INFLUENCE OF SINTERING TEMPERATURE AND HOLDING TIME ON TENSILE STRENGTH AND SHRINKAGE OF PVC SPECIMEN ON INDIRECT PRESSURE-LESS SINTERING PROCESS
Abstract
Sintering process has proven to be a manufacturing process that can produce a mechanical part with high geometric complexity. Development of alternative sintering process is continuously conducted to find the most inexpensive process. A solution process which is called indirect pressure-less sintering were proposed in this research. Generally this process of making a mechanical part is initiated with arranging powder by deposition machine, and continued by sintering process in conventional furnace. Optimal parameters that consist of sintering temperature and holding time in this process were optimized in this paper. PVC powder and sand casting (silica) were used as a material product and supporting powder respectively. The variations of sintering temperature are 100, 105, 110, 115 and 120C, while the holding times are 2, 4, 6 and 8 hours. The optimal parameters were found by measuring tensile strength and shrinkage of specimen. The experiment results showed that dimensional stability of specimen can not be maintained for sintering temperature of 115C with holding time longer than 2 hours. In sintering temperature higher than 120C, PVC material directly starts to melt so that the volume of specimen increased. This was caused by binding of supporting powder. The strength of binding mechanism was measured when sintering temperature was higher than 107C. In sintering temperature of 113C with varying the holding time (2-8 hours) gave the longest variation of tensile strength.
References
S. Das, M. Wohlert, J.J. Beaman, and D.L. Bourell,
Producting Metal Part with Selective Laser
Sintering/Hot Isostatic Pressing, JOM, pp.17-20,
S. Kumar, Selective Laser Sintering: A Qualitative
and Objective Approach, JOM, pp. 43-47, 2003
M.E. Fayed and L. Otten, Handbook of Powder
Science and Technology, 2nd Edition, Chapman and
Hall - ITP, 1997, New York
F. Thummler and R. Oberacker, An Introduction to
Powder Metallurgy, Book 490, The Institute of
Materials, 1993, London
M.W. Barsoum, Fundamentals of Ceramics, 1st,
McGraw-Hill, 1997, Singapore
T.H.C. Child, and A.E. Tontowi, Selective Laser
Sintering of a Crystalline and a glass-filled crytalline
polymer: experients and simulations, ImechE, Vol.
, pp. 1481-1495, 2001
R.M. German, Powder Metallurgy Science, 2nd
Edition, Metal Powder Industries Federation, 1994,
New Jersey
