抄録
In our previous reports, we have investigated the appearances, causes and differences of the scabs in natural and synthetic sand mold.
In the present report, our aim is to show the results of our investigation and research on the types of scabs which appeared in semi-synthetic sand mold. The method we employed in each test is the same as that in the previous investigation.
The conclusions from our tests are as fallows:
1) The properties of high temperatur and the scabs of several kinds of semi-synthetic sand molds which have foundamental combination are shown in the following table.
[Written in non-displayable characters.]
N. Sand : Natural Foundry Sand
S. Sand : Silica Sand
Syn. Sand : Synthetic Foundry Sand
Bent: Bentonite
F. Clay : Fire Clay
“Medium” show that its property is situated between those of N. Sand and Syn. Sand.
2) The oppearances of the scabbing deffects produced in the semi-synthetic sand mold closely resemble that produced by the compressive strength, as high temperature and generally the higher the compressive strength, the greater the scabbing defects.
