Precision metal parts, primarily injection and blow molds for plastic products, with complex metal compositions, are extremely expensive. Sooner or later, stress results in damage and cracks. Repairs by methods currently on the market (primarily argon gas arc welding) alter the metal composition around the repair, and reduce product quality. A defect in the mold arrests the production process, and is detrimental to the plastics factory.

O.R. Lasertechnology offers a technique with which a better solution to such problems can be achieved. The use of laser technology permits precision parts, for example plastic injection molds, to be altered and repaired with an accuracy of up to 50 µm. This process is therefore superior to all other currently used processes.

It is the high quality which provides the primary advantage of this process over other repair processes. Heat sensitive surfaces and coatings are treated in a relatively distortion-free manner. Even the typical discoloration on polished surfaces and branding spots fail to materialize. Adjacent grains remain unchanged. The otherwise extensive post-processing is reduced to a minimum.

The O.R. Lasertechnology laser process makes it possible to treat precision components of all conventional types of molds and tool steels. Beyond this it can also be used for aluminum alloys, copper-beryllium and even exotic materials such as CuZn alloys (which simply cannot be handled by common procedures).

In view of the costs involved to produce a new mold, repairs with the laser process represent a tremendous advantage in cost savings.

A: Basic component
Mold core for the production of bottle caps. Consisting of tool steel 1.2343 combined with CuBe (Copper beryllium)

B: First Step
Edge protection by means of material coating.

C: Second Step
Fusing mold core with insert.

D: Third Step
Entire application of a 0.2 mm thick protection and wear-resistant coating

Materials overview

Material:
Chrome-nickel alloys as well as coatedor nitriding surfaces (see table),hard metal, but not made of particles (the case of very hard metals).

Primary function:
Molds for production of plastic products by injec-tion and blow mold methods

Size of Mold:
All sizes

Mold shape:
All shapes ( including complex forms, difficultto repair by other means).

Overview of Applications

Alteration of:
- scalings
- geometric properties

Repair of:
- surface cracks
- edges and corners
- damaged gates
- worn sealing edges

Weld joining of:
- inserts
- micro-cooling

Application of wear and corrosion resistant layers Fill, Alter and Modify pits and notches.

Technology Description
Laser type: Nd:YAG
Accessories: Fiber optics & special optical attachments, patented filler rods

Process Description
The location to be treated is filled in several operational phases. New material from the filler rod is applied in the course of each phase until finally the desired surface height is reached. Fusion occurs by focusing the laser beam on the surface. A temperature of 1500°C is achieved at the focal point of the laser. A metallurgical bond between base and layer materials occurs due to the fusing of base material in a thin boundary layer. The material added has a special composition that is protected by patent rights. This com-position fulfills the metallurgical characteristics for mechanical, tri-biological, chemical and thermal stress. The transfer of heat to areas outside the welding point is prevented by the extremely short application of energy (10-9seconds).

Advantages

•     extemporaneous changes to the mold can be accomplished quickly and cost efficiently
•     minimal heat-affected zones which results in less finishing work and grinding
•     high precision
•     retention of important metallurgical characteristics