Glossary
Defect
A discontinuity or discontinuities that by nature or accumulated effect (for example, total crack length) render a part or product unable to meet minimum applicable acceptance standards or specifications. See also Discontinuity and Haw.
Degrease
To remove oil or grease from the surface of the workpiece. See Solvent Degreasing.
Deliquescent
The process of melting or becoming liquid by absorbing moisture from the air.
Deliquescent Desiccant Dryer
A pressure vessel containing a collection chamber and a drying desiccant. It has no moving parts, and normally produces a IOOC (500F) dewpoint or lower. Density. The mass or quantity of matter of a substance per unit volume, expressed as grams per cubic centimeter, or pounds per cubic inch.
Density Ratio
See Apparent Density Ratio.
Deposit.
A nonstandard term for thermal spraying deposit.
Deposition Efficiency
The ratio, usually expressed in percent, of the weight of spray deposit to the weight of the material sprayed
Deposition Rate
The weight of material deposited in a unit of time.
Desiccant
A chemical used to attract and remove moisture from air or gas.
Detonation Flame Spraying
A thermal spraying process variation in which the controlled explosion of a mixture of fuel gas and oxygen is utilized to melt and propel the material to the workpiece.
Dewpoint.
Temperature at which moisture will condense from humid vapors into a liquid state.
Discontinuity
An interruption of the typical structure of a coating, such as a lack of homogeneity in the mechanical, metallurgical, or physical characteristics of the material. A discontinuity is not necessarily a defect. See also Defect and Flaw.
Dovetailing
A method of surface roughening involving angular undercutting to interlock the spray deposit.
Dwell Time
The length of time the spray material is exposed to the heat zone which produces and sustains a molten condition.