Optimizing the Cooling Process of Pressure Punches in a Six-Punch Press for Single-Crystal Diamond Growth

This study explores experimental approaches to cooling heat-removal liquids based on distilled water for six-punch press systems operating under a total loading force of 6 × 48.5 MN during the growth of structurally perfect diamond single crystals by the temperature gradient method. A cooling system for hard-alloy punches was designed and fabricated with programmable control of flow rate in each of the six independent circuits, based on punch temperature feedback. Experiments showed that varying the coolant flow rate between 4 and 10 L min–1 at temperatures of 18 and 24°C enables adjustment of the growth-cell control-point temperatures within 18–35°C, respectively. Regulating the punch cooling conditions according to a predefined algorithm during the diamond growth process maintains the optimal temperature distribution within the growth cell, enabling the formation of structurally perfect, flat-faced diamond single crystals weighing up to 20 carats or more.