Processes and mechanisms
Hot isostatic pressing

By definition, isostatic pressurization P at constant temperature produces no change in shape (for an isotropic dense solid), but a slight change in volume according to the equation dV/V = - χdP, where χ is the compressibility of the material at the temperature considered (χ~1/E, E being Young's modulus). An analogy can be made with thermal expansion at constant pressure dV/V = βdT = 3αdT, where β is the coefficient of thermal expansion in volume and α the coefficient of linear thermal expansion.

Since the reduction in volume caused by isostatic pressure results...