Advanced Machining
Advanced Machining/grinding of aerospace alloys and advanced materials
Lead Faculty: Dr. Anil Srivastava
Focus areas:
1. Improving Machinability of Aerospace Alloys
Titanium and Nickel-based alloys have seen increased utilization in military and aerospace applications because of a combination of high specific strength, toughness, corrosion resistance, elevated-temperature performance and compatibility with polymer composite materials. These material properties are essential requirements for certain critical parts such as wing supports and jet engine components. For decades, the high-speed machining of these alloys has created considerable interest to researchers, tool manufacturers and end users because titanium alloys are difficult to machine due to their inherent low thermal conductivity and higher chemical reactivity with other materials at elevated temperatures. We have conducted research on “High Speed Machining of Titanium Alloys” and “Cost-Effective Grinding of Nickel-based Alloys” recently. These studies have been supported by National Science Foundation (NSF) and Department of Defense (DLA-IBIF), respectively.
SEM backscattered-electron micrographs of microstructures developed in Ti–6Al–4V during heating at (a) 750 °C, (b) 815 °C, (c) 900 °C, and (d) 950 °C. The darker phase is alpha, and the lighter phase is beta at the test temperature
Flow stresses of α phase titanium alloy at different rates and temperatures: (a) flow stresses versus strain rates and (b) flow stresses versus temperatures. However, there is lot of work to be accomplished before such technologies are commercialized and used in production. We have ideas to explore and conduct innovative research in developing advanced cutting tool materials, designing and developing process optimization to increase productivity and cost/energy savings for manufacturing industries. This research will help tool manufacturers, in designing optimal tool cutting edge geometry, selecting optimal coatings and to end users in using optimal machining parameters to machine aerospace alloys cost effectively.
2. Machining Optimization Studies on New and Emerging Composite Materials for Aerospace Applications
The stringent requirements of the defense industry, viz., light weight, low operational and manufacturing costs, and increase in the life-time of components have engendered a need for the use of state-of-the-art materials in aerospace vehicles. Carbon-fiber-reinforced-polymers (CFRP) are being extensively used that provide a good combination of strength and hardness along with polymer-like ductility that can be tapped for various defense/aerospace applications. While these advanced material systems are now under study for a variety of defense-related applications, little is known about their machinability and optimizing the machining process for enhancing productivity and cost effectiveness.
Recent breakthrough in composite research has also led to the development of ceramic matrix composites (CMCs) that are being used to manufacture airframes and engine/propulsion system components. Their advantage is the obvious low specific weight, high specific strength over a large range of temperatures and their resistance to damage compared to monolithic ceramic or metal structures. The objective of the research work will be to study and optimize the machinability of these state-of-the-art materials being used in defense applications. Efforts will be pursued both on the experimental and the modeling front in order to study the fundamental material removal mechanisms that come into play in these materials.
While experimental studies are expected to reveal significant insights into the machinability of these materials, modeling studies are vital for enabling an understanding of the fundamental material removal mechanisms responsible for the machining trends observed in these materials. We will use microstructure-based modeling approach for machining of CFRPs and CMCs materials.
3. Recent Publications from this research group
- X. P. Zhang, R. Shivpuri, and A. K. Srivastava, “A New Microstructure-Sensitive Flow Stress Model for the High Speed Machining of Titanium Alloy Ti-6Al-4V”, Journal of Manufacturing Science and Engineering, vol. 139, May 2017, 051006: 1-17,
- Harish Kumar, Sehijpal Singh, and Anil Srivastava, “Parametric Investigations into Internal Surface Modification of Brass Tubes with Alternating Magnetic Field”, Procedia Manufacturing, Elsevier, Vol. 5, 2016, pp. 1234-1248
- Xueping Zhang, Rajiv Shivpuri, Anil K. Srivastava, “Chip Fracture Behavior in the High Speed Machining of Titanium Alloys”, Journal of Manufacturing Science and Engineering, vol. 138, August 2016, pp. 081001: 1-14,
- K. Srivastava and R. Pavel, “Grinding Investigations of Ti-6Al-4V Parts Produced using Direct Metal Laser Sintering (DMLS®) Technology”, International Journal of Mechatronics and Manufacturing Systems, vol. 8, Nos. 5/6, 2015, pp. 223-242,
- Zhang X. P., Shivpuri R., and Srivastava A. K., “Role of Phase Transformation in Chip Segmentation during High Speed Machining of Dual Phase Titanium Alloys”, Journal of Materials Processing Technology. Vol. 214 (12), 2014, pp. 3048-3066,
- H. Yamaguchi, A. K. Srivastava, M. Tan, and F. Hashimoto, “Magnetic Abrasive Finishing of Cutting Tools for High-Speed Machining of Titanium Alloys”, CIRP Journal of Manufacturing Science and Technology, vol. 7, 2014, pp. 299–304,
- C. Nath, S. G. Kapoor, A. K. Srivastava, J. Iverson, “Study of Droplet Spray Behavior of an Atomization-based Cutting Fluid (ACF) System for Machining Titanium Alloys”, Trans. of the ASME - Journal of Manufacturing Science and Engineering, 136(2), 2014, pp. 021004.
- X. P. Zhang, R. Shivpuri, A. K. Srivastava, “Role of Phase Transformation in Chip Segmentation during High Speed Machining of Dual Phase Titanium Alloys”, J. of Materials Processing Technology, 214 (12), 2014, pp. 3048–3066,
- C. Nath, S. G. Kapoor, A. K. Srivastava, J. Iverson, “Effect of Fluid Concentration in Titanium Machining with an Atomization-based Cutting Fluid (ACF) Spray System”, Journal of Manufacturing Processes, 15(4), 2013, pp. 419-425,