Noun
HPHT (uncountable)
Initialism of high pressure, high temperature: a process for creating synthetic diamonds
The Elements. pp. 105–107 Compounds (14% of global use) * Molybdenum disulfide (MoS 2 ) is used as a solid lubricant and a high-pressure high-temperature (HPHT) antiwear agent. Source: Internet
"Ultrahard fullerite" is a coined term frequently used to describe material produced by high-pressure high-temperature (HPHT) processing of fullerite. Source: Internet