| Repairing an aluminum injection mold is tough. If
you try to use an standard TIG welder to fill scratches, digs, gouges, or
machining mistakes the mold the mold gets so hot that the alloy looses its
temper and can distort or crush in the molding machine. But a pulsed micro TIG
welder heats only locally. Filler metal is deposited one pulse at a time,
melting a 1-4mm area. This keeps the temper of the mold and the method of
deposition prevents voids. Then hand smooth, or put the mold back on the mill
and re-machine the surface.
For aluminum mold repair we use the Orion 100c Pulse-Arc Micro-TIG Welder. The weld pulse is triggered by touching the electrode to the work surface. The electrode is automatically pulled back during the arc to prevent the electrode from touching the surface, thus preventing the electrode from sticking. It also keeps the electrode sharp.
The welder can also add modulation to the weld pulse, they call it agitation. This causes the melt pool to crystallize into smaller crystal domains. These small crystal domains are less able to seed the next melt pool to form large contiguous crystals. The result is a more homogeneous fill material. And it is very good at making a fill without trapped voids.
We literally paid for the cost of the welder in 2-3 mold repairs, not even counting the saved down-time when we were able to quickly get back to making valuable parts. Our previous method of repair was to machine a cavity into the mold, machine and bolt in a matching piece of metal and machine that. These welders have 5 to 11 times the peak power of competitive models.
The welder can be operated on standard household voltage and powers.
| Orion 100c Pulse-Arc Micro TIG welder
100 Joule maximum pulse energy
Recommended for aluminum mold repair
|Orion 250s Arm Pulse-Arc Micro TIG welder
250 Joule maximum pulse energy
Rapid pulse mode (up to 5 welds per second)
Recommended for aluminum, copper, steel and stainless steel mold repair