Laser for Microdrilling

Laser is one of the most accurate methods for cutting materials. Its ability to cut all sorts of material makes it a valuable equipment in machine shops all over the world. Flat laser cutting, for example, is used for fast and easy cutting of sheet materials such as metal, plastic and wood. 

The lack of debris makes it all the more important in operations wherein the risk of contamination is a serious issue. Aside from cutting, an application wherein the use of laser tops all other methods is for microdrilling.

Not very long ago, the smallest hole that could be made using the conventional method was the size of a human hair. Advancements in the realm of medical, computer and electronic technology require the drilling of even smaller holes. 

These holes have to be accurate, straight and have the necessary geometric details.

Non-conventional drilling technique was needed which necessitated the development of new machining tools. The ultraviolet light lasers is one of the best tools for microdrilling and other micro machining applications. 

It had high peak power and repetition rates which makes quick work of machining tasks. The quality of the beam produced allowed the drilling of holes with diameters as small as 10 micrometers.

The use of laser for microdrilling has been around for quite a bit of time. The aerospace industry used this method in the production of components of the aircraft turbines. This technique, however, did not catch on quickly for other machining operations. 

This is due to the fact that these types of laser systems used to require a great amount of maintenance. Plenty of replacements such as those of optics and flash lamps have to be done in order to keep the system running.

Graphitization of Diamond Tools

The diamond is the hardest material in the world. It also has a very high temperature tolerance. This makes it one of the most effective components in cutting tools.

Diamond tools are most widely used in superfinishing, otherwise known as microfinishing. This is a metal working process that improves the surface finish of the work piece. This is done by removing the amorphous layer that is left from previous abrasive processes. Superfinishing  creates a cross-hatch pattern on the workpiece. If performed at high and fine speeds, this can create a mirror-like finish.

Diamond tools, however, are not suitable for cutting steel as this can result to severe wear on the tool. This makes it inefficient and unprofitable .

The severe wear occurs due to graphitization, a process that turns the crystal structure of a diamond into a graphite crystal structure. Carbon steel and alloys with cobalt, nickel and titanium can cause graphitization.

Plenty of efforts have been made in an attempt to make diamond tools viable for cutting steels. One method is to perform the cutting process in specially designed chambers that prevent graphitization.

Since graphitization only happens at temperatures above 200 degrees Celsius. In a cryogenic chamber, a diamond tool can be used for cutting steel without the problem caused by graphitization. The problem with this and other similar methods is that the equipment needed for the setup is quite expensive which is not ideal for many who are running a smaller operations.