An Experimental Study on Fitting Condition of Non-Precious Cast Crown Alloys
Part 1. A Comparison of Burnout Temparature
1986 Volume 30 Issue 1 Pages 1-11
Details
1986 Volume 30 Issue 1 Pages 1-11
There are many problems centered around the use of Ni-Cr alloy, fitting, casting flow and casting shrinkage to name but a few are areas that must be deal with. Ni-Cr alloy does possess some very good physical and mechanical qualities, specifically; an ability to withstand wearing, hardness, heat conductivity, specific gravity plus many other points.
The object of this study is to explore the many positive points of Ni-Cr alloy.
Three kinds of investments and alloys were used in this study. And 5 temperatures were used as a base to determine the better burn out temperature of the wax patterns, 500, 600, 700, 800 and 900°C.
The difference of fitting conditions, casting shrinkage and roughness on the surface was measured.
Conclusion:
1. At all temperatures, the casted alloy only expanded, no shrinkage occured.
2. Fitting conditions corresponded proportionally to the size of the metal mold, the larger the mold the better the fit.
3. The texture of Fitlloy 50 type II was found to be finer than that of Summalloy Soft and Summalloy Regular casted alloy.
In addition, the casted alloy which was buried in Crown-vest was rougher than either Ceravest and Summa-vest.
4. In addition, it was found that the finer the texture the better the fit.
