Improving the RF Performance of Ceramics Using Laser Assisted Machining

Year 2020, Volume: 1 Issue: 4, 93 - 100, 01.12.2020

Emre Gungor Ebrar Ozbek Seymur Shukurov Orhan Çakır

Abstract

The radio frequency (RF) performance of military missiles depends largely on the dimensional tolerances of the ceramic radome (Si3N4, Mullit, Al203) in the missile. Small deviations and differences in precise tolerances on both the inner and outer surface of the radome affect the insertion loss of the radome wall, which has a negative impact on the RF performance of the missile. When these effects are taken into consideration, it is seen that surface sensitivity and surface integrity are important parameters in the machining process of ceramics. Ceramics are difficult to process with conventional processes because they are hard and brittle, as well as high costs. The current method for machining ceramic radome surfaces is the type of machining made with conventional CNC machines using a special cutting tool and cooling system. In this study, laser assisted machining (LAM) technique was proposed to overcome the disadvantages and reduce the surface roughness. While the approximate loss of insertion value for ceramic radomes produced by conventional methods is around 2.5 dB, it was predicted that this value can be obtained around 1.5 dB by laser assisted processing which is one of the hybrid manufacturing methods. Computer aided simulations were performed based on the surface roughness values obtained from the surface roughness measurements made after both machining methods. From the results of these simulations, it is seen that laser reinforced processing method has a significant contribution to the signal transmission efficiency of ceramic radomes.

Keywords

Hybrid Manufacturing, Laser Assisted Machining (LAM), Ceramics, RF Performance, Insertion Loss Simulation

References

• [1] Konig, W. & Wagemann, A. (1990). Machining of Ceramic Components: Process-Technological Potentials, Machining of Advanced Materials, NIST Special Publication, 847, 3–16.
• [2] Chryssolouris, G., Anifantis, N. & Karagiannis, S. (1997). Laser Assisted Machining: An Overview Laboratory for Manufacturing Systems, The Journal of Manufacturing Science and Engineering, 119, 766-769.
• [3] Uehara, K. & Takeshita, H. (1986). Cutting ceramics with a technique of hot machining, Annals of the CIRP 35, 55–58.
• [4] Konig, W. & Zaboklicki, U. (1993). Laser-Assisted Hot Machining of Ceramics and Composite Materials, Machining of Advanced Materials, NIST Special Publication, Volume 847, 455–463.
• [5] Banik, S. R. & Kalita, N. (2018). Recent trends in laser assisted machining of ceramic materials, Materials Today: Proceedings, 5(9), 18459-18467.
• [6] Chang,C. & Kuo, C. (2007). Evaluation of surface roughness in laser-assisted machining of aluminum oxide ceramics with Taguchi method, International Journal of Machine Tools and Manufacture, 7(1), 141-147.
• [7] Muženič, D., Dugar, J., Kramar, D., Jezeršek, M., & Pušavec, F. (2019). Improvements in Machinability of Zinc Oxide Ceramics by Laser-Assisted Milling. Strojniški vestnik - Journal of Mechanical Engineering, 65(10), 539-546.
• [8] Yang, B., Shen, X., & Lei, S. (2009). Mechanisms of edge chipping in laser-assisted milling of silicon nitride ceramics, International Journal of Machine Tools and Manufacture, 49(3–4), 344-350.
• [9] Li, Z., Zhang, F., Luo, X., Chang, W., Cai, Y., Zhong, W. & Ding, F. (2019). Material removal mechanism of laser-assisted grinding of RB-SiC ceramics and process optimization, Journal of the European Ceramic Society, 39(4), 705-717.
• [10] Dong, X. & Shin, Y.C. (2014). Laser Machining and Laser-Assisted Machining of Ceramics, Comprehensive Materials Processing, 9, 219-234.
• [11] Przestacki, D. & Jankowiak, M. (2014). Journal of Physics: Conference Series, 483, 012019, 1-7.
• [12] Rozzi, J.C., Pfefferkorn, F.E., Shin, Y.C. & Incropera, F.P. (1999). Experimental Evaluation of the Laser Assisted Machining of Silicon Nitride Ceramics, ASME. J. Manuf. Sci. Eng., 122(4), 666–670.
• [13] Song, H. & Dan, J. (2018). Experimental investigation of machinability in laser-assisted machining of fused silica, The International Journal of Advanced Manufacturing Technology, 97(1–4), 267–278.
• [14] Chryssolouris, G. (1991). Laser Machining: Theory and Practice, Springer-Verlag, New York
• [15] Rebro, P.A., Shin, Y.C. & Incropera, F.P. (2002). Laser-Assisted Machining of Reaction Sintered Mullite Ceramics, ASME. J. Manuf. Sci. Eng., 124(4), 875–885.
• [16] Sharif Ullah, A.M.M. & Tamaki, J. (2010). Modeling and Simulation of 3D Surface Finish of Grinding, Advanced Materials Research, 126-128, 672-677.
• [17] Felho, C. & Kundrak, J. (2014). CAD-Based Modelling of Surface Roughness in Face Milling, World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering, 8(5), 814-818.
• [18] Fischer-Cripps, A.C. (2011). Nanoindentation, Mechanical Engineering Series, Third edition, Springer-Verlag New York, USA.
• [19] Lukianova, O.A. & Sirota, V.V. (2017), Dielectric properties of silicon nitride ceramics produced by free sintering, Ceramics International, 43(11), 8284-8288.