The outline of lacquer dewetting or eyeholing on electroplytic tin plate and the results of lacquer flow test were studied.
A small drop of the standard lacquer was flowed on the tin plate to form triangular figure.
The test result was compared with each of ten standard samples to determine the degree of lacquer dewetting on the specimen plate.
The relationship between the lacquer flow test value and actual dewetting by coating was fairly good, although it was sometimes out of order when actual coating was affected by other factors.
Contact angle of lacquer on the specimen plate was measured; however, the relationship between the lacquer flow test value and the contact angle was not always good.

View full abstract

Fundamental researches on vibratory barrel finishing were conducted, and the following results were obtained.
(1) The vibration of the barrel wall was elliptical, which made the mass circulative. The moving velocity of the mass was larger with the increase of rotating velocity and charged load.
(2) The weight of removed metal was larger with the increase of rotating velocity, but not proportional to the moving velocity of abrasives; it was significantly affected by the dynamic force of abrasives.
(3) The grinding ability of the barrel was most effective in the bottom and less in the sliding zone.
The result was quite reverse to ordinary rotating barrels.

View full abstract

The abrasion test was conducted on samples of cast iron, produced by various methods and annealed at various temperatures, with a rotor made of pearlite matrix annealed at 550°C. The following results were obtained.
1) The residual stress of the specimen produced in gravity green sand mold (specimen mark; L) was greater than that of specimen in dry sand mold (Q) by centrifugal casting. The residual stress gradually decreased with the rise of annealing temperature when it was below 450°C; however, the stress was rapidly removed at 450-550°C.
2) The relation between annealing temperature and wear loss was examined. Under the condition of the wear with mechanical rupture, the minimum wear loss was observed at 450-550°C in specimen L, or at 550-600°C in Q.
3) When residual stress increased to a certain value, rapid increase of wear loss was observed.
The critical value of the residual stress was called “Critical residual stress for wear.”

View full abstract