- Quartz
- A form of silica occurring in hexagonal crystals which are
commonly colorless and transparent, but sometimes also yellow,
brown, purple, green, etc. It is the most common of all solid
minerals.
See also Silica
- Quartzite
- A compact granular rock composed of quartz. It is a
metamorphosed sandstone, and siliceous cement is often so
blended with the quartz grains as to give the rock a nearly
homogeneous texture. Primary materiel in silica brick.
- Quench Crack
- A crack resulting from thermal stress induced during rapid
cooling or quenching, or from stresses induced by delayed
transformations some time after the article has been fully
quenched.
- Quench Severity
- The quench severity is characterized by the H value and relates
to the rate of temperature change during quenching.
- Qenching
- Rapid cooling of hardening; normally achieved by immersion of
the object to be hardened in water, oil, or solutions of salt or
organic compounds in water.