The machining process requires the use of tough cutting tools made from materials like tungsten carbine. Often, these tools use physical vapor deposition (PVD) coatings to enhance cutting ability and improve longevity. However, aluminum based PVD coatings tend to have a rough texture which causes issues when machining materials like titanium. Shortened tool life is typically caused by titanium adhering to the coating, forming a nitride (TiAlN) on the surface of the cutting tool. This can lead to the dulling and breakage of the tool, and/or damage to the working surface. As the tool begins to wear, it will eventually need to be replaced. When machining large volumes of material, such is the case for various aerospace components, having to replace the tool can cost a lot of time and money. It is of great interest to decrease tool replacement and increase machining throughput and quality. In this study, a pin on disc test was designed to model a real cutting process so as to rank the tribological behavior of different material pairs, cooling, and lubricating methods. A small scale tribological approach offers a cost effective, and repeatable method for analyzing a complex problem. A tungsten carbide pin (coated and un-coated) was set to cut into a titanium disc under gradually increasing load and constant cutting speed. Coolants such as liquid nitrogen, and emulsions were directed into the working interface to reduce heat and provide lubrication. When designing the test, the maximum applied load, friction force, friction noise, friction decay, acoustics, and disc cut surface were considered. Friction coefficient, wear on the pin and disc, and load carrying ability were measured for each combination to determine an appropriate ranking. Higher load carrying ability with smooth and uniform wear track was desired. Based on the pin on disc test results, certain combinations were chosen to run finishing operations on full scale machining of titanium components. Results indicated a correlation to the bench test, as the material pairs out performed previously used methods. The implementation of these combinations lead to an increase in cutting tool life and up to an 83% reduction in cutter usage when machining large components. For the finishing operation, a proper selection of coating and coolant lead to lower tool wear, less heat generation, and smoother working surfaces. Although a small scale bench test model cannot completely replicate the real life process, with careful consideration of the system a comparative ranking of materials can be achieved.    

   

   

   


Tribological Study of Materials and Coolants for Effective Cutting Tool Life

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

IMECE2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.