Scope:

ASTM F77 determines the apparent density of ceramics used in electronic devices and semiconductor applications.

Test Procedure:

Important apparatus and substances used for the ASTM F77 method are: 1. Specific gravity balance 2. Boiled distilled water 3. High-density liquid.

A plummet is dangled on the left side of the balance and the vernier and the beam rider are set at zero reading. The balance is adjusted to null. A cylinder, provided with the balance, is filled with boiled distilled water and placed on the platform directly under the plummet. The platform is raised until 0.5 inches of the plummet is below the surface of the liquid. The temperature and balance readings are recorded. The platform is then brought down, water is removed from the cylinder and the plummet and cylinder are allowed to dry. 

Further, in the ASTM F77 testing, the ceramic sample is placed in a beaker containing high density liquid. Because the ceramic sample is less dense than the liquid, the ceramic will float on the surface of that liquid. Water is added to the high density liquid until its density equals that of the ceramic sample. This is indicated by the sample sinking below the surface, and getting suspended in the liquid. The sample is removed from the liquid as soon as this happens. 

The liquid from the beaker is poured into the cylinder. The platform is raised and the plummet immerses in the liquid. The counterpoise weight is placed. The beam rider and the vernier are manipulated to obtain the null point. The temperature and balance readings are recorded.

 Specimen size:

The maximum dimension of the ceramic sample as per ASTM F77 should be 25 mm (1 inch) and porosity should be zero or discontinuous. 

Data:

The apparent density of the ceramic sample for ASTM F77 is calculated as follows:

D = (S_fh/S_w) × density of water at T_w

Where

D = apparent density.
T_w = temperature of the water.
T_fh = temperature of the high density liquid,
S_w = balance reading with plummet in water, S_fh = balance reading with plummet in high-density liquid.

Conclusion:

ASTM F77 is used to determine the apparent density of ceramic parts used in electronic devices and semiconductor applications with a maximum dimension of 25 mm and having zero or discontinuous porosity.