| 摘要 |
<p>A method of making a heated injection molding nozzle (10) with an integral tip insert (44). First, an inner portion (12), an outer collar portion (20), and an electrical heating element (32) are made and integrally brazed together in an vacuum furnace (80) using a first nickel alloy brazing material (76). Then a tip insert (44) is made having a desired configuration and seated in the front end (16) of the inner portion (12) and a second nickel alloy brazing material (82) is applied around it. The second brazing material (82) has a melting temperature which is substantially below that of the first brazing material (76). The tip insert (44) is then integrally brazed in place by heating them to a temperature above the melting temperature of the second brazing material (82) and below the melting temperature of the first brazing material (76). In addition to not affecting the metallurgical bonding between the other components, this allows the tip insert (44) to be easily removed for replacement by again heating the nozzle (10) to this same temperature.</p> |
