An eddy current technique is developed for the measurement of reinforcement and intermetallics concentrations in extruded particulate-reinforced metal-matrix composites. The technique employs a theoretical conductivity model which accounts for the constituent phases, together with a measurement of two anisotropic conductivities on the composite, for determining the reinforcement and intermetallics volume fractions.Towards implementation of this technique, an analytical model is described which relates the anisotropic conductivities of extruded particulate-reinforced composites to their microstructures. The volume fractions were calculated using eddy current measurements made on a wide range of silicon carbide particulate (SiC,) reinforced aluminum matrix composite extrusions. The calculated values are shown to be in good agreement with the actual metallographically measured volume fractions of the reinforcement and intermetallics. The technique may be adopted for an on-the-fly assessment of product quality in a processing environment.
1. Beissner, R. E., G. L. Burkhardt and J. L. Fisher. 1992. "Eddy Current Measurements of Fiber Volume Fraction in Metal Matrix Composites," presented at the Quantitative Nondestructive Evaluation Conference, La Jolla, CA.
2.
2. Liu, X. C.1993. "Application of Electrical Resistance Method in Study of SiC/Al Composite,"Advanced Composites Letters, 2(2):61-64.
3.
3. Liaw, P. K., R. E. Shannon and W. G. Clark. 1990. "Correlation of Microstructural Characterization with Nondestructive Evaluation of Al/SiCP Metal Matrix Composites," in Fundamental Relationships between Microstructure and Mechanical Properties of Metal Matrix Composites, P. K. Liaw and M. N. Gungor, eds., Warrendale, PA: TMS-AIME, pp. 581-615.
4.
4. Liaw, P. K., R. E. Shannon, W. G. Clark, Jr. and W. C. Harrigan. 1991. "Process-interactive Nondestructive Evaluation for Metal Matrix Composites," in Morris E.Fine Symposium, P. K. Liaw et al., eds., Warrendale, PA: TMS-AIME, pp. 193-208.
5.
5. Liaw, P. K., R. Pitchumani, S. C. Yao, D. K. Hsu, B. Foster and H. Jeong. 1993. "Eddy Current Characterization of Silicon Carbide Reinforced Aluminum Metal-Matrix Composites:" in Damage in Composite Materials, G. Z. Voyiadjis, ed., The Netherlands: Elsevier Science Publishers B. V., pp. 249-282.
6.
6. Jeong, H., D. K. Hsu, R. E. Shannon and P. K. Liaw. 1993. "Characterization of Anisotropic Elastic Constants of Silicon Carbide Particulate Reinforced Aluminum Metal Matrix Composites. Part I: Experiments,"Metallurgical Transactions A, submitted.
7.
7. Mott, G. and P. K. Liaw. 1988. "Correlation of Mechanical and Ultrasonic Properties of Al-SiC Metal-Matrix Composite:"Metallurgical Transactions A, 19A:2233-2246.
8.
8. Hashin, Z.1983. "Analysis of Composite Materials-A Survey,"Journal of Applied Mechanics, 50:481-505.
9.
9. Taya, M. and R. J. Arsenault. 1989. Metal Matrix Composites: Thermomechanical Behavior. New York: Pergamon.
10.
10. Pitchumani, R., S. C. Yao, P. K. Liaw, R. E. Shannon, D. K. Hsu and B. Foster. 1992. "A Simplified Model for Estimating the Anisotropic Conductivities of Al/SiC, Composites for Process Monitoring,"Transport Phenomena in Materials Processing and Manufacturing, ASME-HTD196:201-207.
11.
11. Pitchumani, R., P. K. Liaw, S. C. Yao, D. K. Hsu and H. Jeong. 1994. "Theoretical Models for the Anisotropic Conductivities of Two-and Three-Phase Metal-Matrix Composites,"Acta Metallurgica et Materialia, submitted.
12.
12. Behrens, E.1968. "Thermal Conductivities of Composite Materials,'Journal of Composite Materials, 2(1):2-17.
13.
13. Han, L. S. and A. A. Cosner. 1981. "Effective Thermal Conductivities of Fibrous Composites,"ASME Journal of Heat Transfer, 103:387-392.
14.
14. Pitchumani, R. and S. C. Yao. 1991. "Correlation of Thermal Conductivities of Unidirectional Fibrous Composites Using Local Fractal Techniques,"ASME Journal of Heat Transfer, 113(4):788-796.
15.
15. Pitchumani, R. 1992. Modeling the Thermal Properties and Processing of Composite Materials, Ph.D. Thesis, Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA.
16.
16. Marshall, R. C., J. W. Faust, Jr. and C. E. Ryan, eds. 1974. Silicon Carbide 1973. Columbia, SC: University of South Carolina Press, p. 673-673.
17.
17. Schroder, K., ed. 1983. CRC Handbook of Electrical Resistivity of Binary Metallic Alloys. Boca Raton, FL: CRC Press, Inc.
18.
18. Touloukian, Y. S., ed. Thermophysical Properties of High Temperature Solid Materials, Vol. 6 Part 1: Intermetallics. New York: The MacMillan Company.
19.
19. Tottle, C. R.1984. An Encyclopedia of Metallurgy and Materials. Great Britain: The Metals Society, MacDonald and Evans.
20.
20. "Properties and Selection: Nonferrous Alloys and Pure Metals," in Metals Handbook, 9th ed., Vol. 2, ASM Metals Park, OH.
21.
21. 1929. "Resistivity of Alloys," in International Critical Tables, Vol. 6 New York: McGraw Hill.
22.
22. Mondolfo, L. F.1976. Aluminum Alloys: Structure and Properties. London: Butterworths.
23.
23. Davis, G. V.1986. Numerical Methods in Engineering and Science. Boston: Allen and Unwin.
24.
24. Libby, H. L.1979. Introduction to Electromagnetic Nondestructive Test Methods. Huntington, NY: R. E. Krieger Publishing Company.
25.
25. Shannon, R. E., P. K. Liaw and W. C. Harrigan, Jr.1992. "Nondestructive Evaluation for Large-Scale Metal-Matrix Composite Billet Processing,"Metallurgical Transactions A, 23A(5):1541-1549.
26.
26. Hilliard, J. E. and J. W. Cahn. 1961. "An Evaluation of Procedures in Quantitative Metallography for Volume-Fraction Analysis,"Transactions of the Metallurgical Society of AIME, 221:344-352.
27.
27. Hatta, H. and M. Taya. 1985. "Effective Thermal Conductivity of a Misoriented Short Fiber Composite,"Journal of Applied Physics, 58(7):2478-2486.
28.
28. Char, B. W., et al. 1991. Maple V Language Reference Manual. New York: Springer-Verlag.
