Micro Laser Assisted Machining Device, Micro-LAM

Product: Machine for improved Laser Assisted Machining (LAM)
Development Stage: Pilot-Scale Manufacturing
Primary Inventor: John Patten, PhD, Manufacturing Engineering Department 
Scientific Publication: Ravindra et al., Precision Engineering, 2012, 36, pp. 364-367.
License Status:  Sub-license Available 
Patent Status: US WES019 P308; 8,933,366
Reference: 2005-007

Laser-assisted machining (LAM) hard, brittle materials, such as semiconductors and ceramics, utilizes a laser to heat an area to soften it before it is machined. The rest of the work piece is not exposed to the laser, sparing it from permanent heat damage. Pre-heating the area to be machined significantly reduces fracturing during the machining process. Because this method limits the softening effect of the material to the area to be machined and does not heat the entire work piece, it has gained wide acceptance. 

Application of laser radiation in advance of a machining tool makes the LAM apparatus large, complicated, and expensive to run.  A large laser source and a significant amount of power (kW) are required to produce the very high temperatures needed to cause localized heating and deformation (i.e.–thermal softening) of semiconductors and ceramics and other brittle materials. 

Technology Description

The Micro-LAM apparatus and process developed by Dr. John Patten addresses many of the shortcomings of conventional LAM. The Micro-LAM device machines semiconductor and ceramic materials by simultaneously heating and deforming with high pressure the microscopic area of the material that is in contact with the machining tool tip, a diamond tip. 

Under the extremely high pressures occurring at the contact interface between the diamond tip and work piece, the material undergoes a high pressure, phase transformation (HPPT). Laser energy is simultaneously applied to the interface, being transmitted through the diamond tip and being focused exactly on the HPPT material, heating the material at the contact point. Because HPPT materials become opaque, they absorb laser radiation of specific wavelengths (IR), while the rest of the work piece remains transparent and transmits the laser energy. This results in very selective heating and softening of the HPPT area, while the bulk of the material is unaffected.

Compared to a conventional LAM apparatus, the Micro- LAM device has reduced tool wear, minimizing down time, and is smaller and more energy efficient. Because of simultaneous application of heat and pressure, the material is machined quickly and smoothly, significantly decreasing production time and cost, and increasing finished product precision.

Potential Benefits

•    Greater machining precision
•    Faster machining times
•    Reduced tool wear
•    Reduced down time
•    Energy efficient machining
•    Improved product quality

Contact

D. Clark Bennett
(269) 387-8218
Director of Technology and Innovation Advancement