| 摘要 |
<p>A compression forming process includes use of a die comprising: a bottom die (10); a punch (20), mobile with respect to the bottom die (10); an air escape route from the bottom die (10). The process comprises following steps: a) inserting a batch of material in a form of small pieces in the cavity of the bottom die, b) nearing the two parts of the die to one another, up to defining a forming chamber, c) supplying heat to the particles of the batch, during step b), by heating the internal surfaces of the chamber of the bottom die and the punch, increasing a degree of fluidity of the particles with growing values over a period of time, starting from a minimum value at the start of step b) up to a maximum amount, at the end of step b). In step c) the process comprises heating the particles of the batch in a differentiated way so that the particles located at the upper internal surface (21, 31) are brought to values of fluidity, growing over time, with a delay with respect to the particles located at the lower internal surface (11).</p> |
