Abstract:
Conventionally, unfilled wax has been used as
a universal pattern material for the investment casting
process. With increase in demand for accurate dimensions
and complex shapes, various materials have been
blended with wax to develop more suitable patterns for
investment casting in order to overcome performance
limitations exhibited by unfilled wax. The present article
initially reviews various investigations on the development
of investment casting patterns by exploring pattern
materials, type of waxes and their limitations, the effect of
filler materials and various additives on unfilled wax, wax
blends for pattern materials, plastics and polymers for
pattern materials and 3D-printed patterns. The superiority
of filled and polymer patterns in terms of dimensional
accuracy, pattern strength, surface and flow properties
over unfilled wax is also discussed. The present use of 3D
patterns following their versatility in the manufacturing
sector to revolutionize the investment casting process is
also emphasized. Various studies on wax characterization
such as physical (surface and dimensions), thermal (thermogravimetric
analysis and differential scanning calorimetry),
mechanical (thermomechanical analysis, tensile stress testing, dynamic mechanical analysis) and rheological
(viscosity and shearing properties) are also discussed.
