Investigation of Mechanical Properties of Powder Metallurgy Parts with Control of Microstructure


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In the present work, two kinds of steel powder were (Distaloy HP-1 & Ultrapac-LA) selected and subjected to powder metallurgy processing. For Ultrapac-LA, a heterogeneous microstructure consisting of tempered martensite, nickel-rich ferrite, divorced pearlite and nickelrich regions surrounding pores was observed. For Distaloy HP-1 in slow cooling rates (0.4 °C.s-1), the amounts of martensite and bainite varied between 50-60% and 30-40%. However, for fast cooling rates (1.2 °C.s-1), the variation was between 70-80% and 10-20%. The mechanical properties of the prepared samples were studied with controlled production conditions such as cooling rate and heat treatment. The increasing porosity was found to play an important role in the tensile stress and fatigue strength. The ultimate tensile strength and fatigue strength were more than 1000 MPa and 400 MPa in this research (for Distaloy HP-1, 7.2, 0.5% carbon content and fast cooling rates). Macroscopic examination of the fracture surfaces for all specimens revealed that fatigue crack growth and final fracture regions were brittle and without noticeable permanent deformation. The final fracture regions for all tests were very similar, and the final fracture in these two material conditions revealed brittle macrobehavior and ductile microbehavior.



Materials Science Forum (Volumes 534-536)

Edited by:

Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim






H. Khorsand and S.M. Habibi, "Investigation of Mechanical Properties of Powder Metallurgy Parts with Control of Microstructure ", Materials Science Forum, Vols. 534-536, pp. 297-300, 2007

Online since:

January 2007




[1] H. Danninger, D. Spoljaric, B. Weiss, Microstructural Features Limiting the Performance of P/M Steels, The International Journal of Powder Metallurgy, Vol. 33, No. 4, pp.43-53 , (1997).

[2] D. Spoljaric, H. Danninger, B. Weiss and R. Sticker, Fatigue Behavior of Mo-Alloyed Sintered Steels and its Consequences for Application", PM Auto, 96 Conf., Iran, Isfahan, April 15-19 , (1996).

[3] M. Habibi, H. Khorsand, M. Ashtari & K. Jonghorban, Fatigue Behavior of PM Steel ULTRAPAC-LA, PM02 Conf., India, New Delhi, January 22-24 , (2002).

[4] H. Khorsand, M. Habibi, M. Ashtari & H. Yoozbashizadeh, The Role of Heat Treatment on Wear_Behavior of Powder Metallurgy Low Alloy Steels, PM02 Conf., India, New Delhi, January 22-24, (2002).

[5] Suleyman Saritas, Robert Causton, W. Brian James, and Alan Lawley, Effect Of Micro structural In homogeneities On The Fatigue Crack Growth Response of a Prealloyed and Two Hybrid P/M Steels , PM2TEC 2002, International Conference on Powder Metallurgy & Particulate Materials, Orlando, Florida, June 16-21, (2002).

[6] E. A. Sager, R. I. Stephens , and T. Prucher, Influence Of Density And Sintering Temperature On Monotonic, Cyclic and Low Cycle Fatigue Behavior Of FL4405 High Strength P/M Steel, Powder Metallurgy, Vol. 41, No. 2, pp.103-108, (1998).

DOI: 10.1179/pom.1998.41.2.103

[7] B. Lindqvist. Influence of Microstructure and Porosity on Fatigue Properties of Sintered Steels, Modern Developments in Powder Metallurgy, Vol. 21 compiled by P.U. Gummeson and D.A. Gustafson, Metal Powder Industries Federation, Princeton, NJ., pp.67-82 , (1988).

DOI: 10.1080/10426919008953287

[8] Anders Bergmark, Luigi Alzati and Ulrika Persson, Fatigue Crack Initiation In Pm Steel, PM2TEC2002, International Conference On Powder Metallurgy & Particulate Materials, Orlando, Florida USA, June 16 - 21, (2002).

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