Extreme High Speed Laser Application (EHLA) for Titanium Cylinders Bores

There are many mechanical systems that utilize cylinder-piston hardware such as hydraulic cylinders, reciprocating engines, etc. Many of the systems experience excessive wear of the cylinder wall that require replacement at high cost, especially if the cylinder is comprised of expensive alloys such as titanium. To extend the service life of these expensive components, application of coatings to cylinder bores with hard, wear-resistant and corrosion-resistant coatings are often used. However, many commercially available coating applications for titanium substrates introduce a large heat-affected zone (HAZ) causing delamination, reduced fatigue life, distortion, and surface cracking. There are some select coating processes available today that have minimized the effect on base titanium material, but the processes still ultimately result in early failure of the component due to heat-affected zone penetration. For applications such as damper or hydraulic cylinder housings, electrodeposited have been used which are susceptible to premature failure due to delamination and spalling.   EHLA coatings have proven to achieve strong bonding to substrate materials and will eliminate the issue of delamination and spalling in service. Traditional Laser Metal Deposition (LMD), with reduced energy transfer to the substrate, has been successful in the application of wear coatings on alloys and has minimized the HAZ. For large-area coatings with LMD, the area rates currently achievable (coated area per time) are often too small and the minimum layer thickness that can be produced is too great in many cases. For these reasons, the Extreme Highspeed Laser Application (EHLA) process was developed by the Fraunhofer Institute for Laser Technology ILT.  The LMD and EHLA processes were initially developed for Line Of Sight (LOS) applications but recent developments have made Non Line Of Sight (NLOS) applications possible and practical. For this Phase I effort, ES3 proposes to evaluate three different mixed matrix materials for potential use as a hard, wear coating on Titanium 6-4 (Ti-6-4) hydraulic cylinder wall surfaces.