Shop Metalworking Technology speaks with design engineer Russ Reynoso about micro cutting tools
How you define micro tools?
We define micro tools as any diameter 0.20 mm and smaller. However, from an industry prospective, it seems most like to label micro tools as any tool with a diameter of 3 mm and smaller. Obviously, as diameters shrink, so do the associated tolerances. It’s not uncommon to work with features that have a tolerance of plus or minus 1 micron. It’s very rare to find a requirement to extend beyond.
What are the challenges of micro machining and the role cutting tools play in overcoming them?
The biggest challenge to micro machining is patience. The rate of removal is greatly reduced as diameters reach the micro levels. Multiple passes are needed to ensure tool failure does not occur. As a manufacturer, we also have to be aware of advances in carbide materials. Materials that were developed 10-20 years ago are no longer applicable for micro machining processes.
What impact do materials and different types of coatings have on micro cutting tools?
We look for consistency in materials and coatings. Smaller diameters are very difficult to coat so we need to be dilligent in inspecting for any flaws on coated product. We also look for consistent grain structures in the materials we use for tooling. All materials need to have a strong balance in hardness for good edge retention and tenacity to absorb all shock and bending forces. We have explored nano grain structures with very good performance results.
What is the market for micro tools and micro machining? Is there growth in micro-sized parts with high tolerance finishes?
Yes, we feel there is a strong market for micro tools. The amazing thing is, we see opportunities in all substrate materials you’ll typically see being machined with larger tooling. We see a lot of activity particulalry in the semiconductor industry. We feel the demand will continue to drive diameters smaller and smaller.
What key changes have occurred in design and geometry?
Both raw materials, manufacturing equipment, along with gauging has helped us reach designs we were not able to do in the past. Variable design features allow us to reach performance levels we were not able to reach in the past.
How do you determine performance and quality of a micro tool with the influx of tooling from offshore, low-cost countries that replicate big brand designs?
It’s fairly difficult with so much technology available worldwide. A trained eye on occassion, however, can spot some questionable workmanship. One telling opportunity is to review a higher quantity of tooling and measure the variability. You cannot see consistency with one or a few tools. But like anything else, performance will be the true referee.
What changes have been made to micro tools to extend tool life?
It starts with the raw material. As mentioned prior, material development occurrs rather quickly and has a significant impact on tool performance. Obviously coatings are also under a rapid development cycle. We are often introduced to many new coatings. Most do show a consistent positive influence on machining performance. It depends on the application and the desired results.
What is the R&D focus for the micro tool industry?
We are constantly looking at not only developing new products, but also improving current designs. We spend a lot of time testing carbides for various applications. We investigate new capabilities our manufacturing process develops. We work with a lot of customers who are looking to us to either help them develop a new process or improve their current one. Our engineers in the field do a great job in defining new trends and future demands. It’s extremely important to make sure we are aligned with the path the industry is moving toward. SMT
Russ Reynoso is the design engineering manager for Kyocera Tycom Corp., based in Costa Mesa, CA. Kyocera Tycom Canada Ltd. is based in Mississauga, ON.