Computer aided determination of porosity in sintered steels

• Autorzy: Dobrzański L. , Musztyfaga M. , Actis Grande M. , Rosso M.
• Języki publikacji: PL

Abstrakty

EN

Purpose: Purpose of this paper was to apply a computer method of open porosity analysis for determination of porosity in sintered Astaloy CrL and CrM powders. Design/methodology/approach: The powders used in the present papier are pre-alloyed iron-base powders containing low amounts of chromium and molybdenum. The amount of graphite which is mixed with the iron-base powder is 0.6% and lubricant is 0.75%. Green compacts were sintered in a vacuum furnace at 1120°C for 30 minutes in vacuum and rapidly cooled in nitrogen at four different rates: high cooling (7°C/s and 6.5 °C/s) and medium cooling (1.6°C/s) low cooling (0.3 °C/s). Next the samples were tempered in vacuum in the same furnace at 200°C for 60 minutes and cooled in nitrogen, with the exception of low cooling. Obtained samples were examined by light optical microscopy (LOM) for microstructure observation and scanning electron microscopy (SEM). Findings: The investigations of porosity in the pre-alloyed steels were performed using ”Image-Pro Plus 4.5” computer program. Leica light microscope (MEFA4) was applied to prepare series of micrographs. The microstructures were observed at 100x magnification and recorded as*jpg files. After calibration of the digital images, the perimeter, area, diameter, roundness, Feret max were calculated. Practical implications: The program has some limitations (built in mathematical functions), which made difficult to obtain some results automatically. Originality/value: The obtained results prove that this program is very useful in the statistical analysis of microstructures, because it saves the time during calculations and is well suited for checking sintered materials.

Słowa kluczowe

PL

metalurgia proszków

EN

powder metallurgy; Sintering pre-alloyed astaloy CrL and CrM steels; Computer method of porosity analysis

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2009
• Tom: Vol. 38, nr 2
• Strony: 103--111
• Opis fizyczny: Bibliogr. 15 poz.

Twórcy

autor

Dobrzański L.

autor

Musztyfaga M.

autor

Actis Grande M.

autor

Rosso M.

• Division of Materials Processing Technology and Computer Techniques in Materials Science, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland,

Bibliografia

• [1] S.J. Kowalski, The Engineering of porosity materials. Engineering of porous materials, Publishing Technical University, Poznań, 2004, 9-20.
• [2] A. Cyunczyk, The engineering basis of metallic sinters, Outhouse Publisher, Rzeszow, 2000, 132-133.
• [3] J. Banaszak, The Engineering of porosity materials: a laboratory, Publishing Technical University, Poznan, 2005, 6-7.
• [4] W. Sowa, M. Sułowski, The effect of processing variables on the porosity of structural PM manganese steels, Gingers and Metals R51/3 (2006) 155-162.
• [5] M. Sułowski, Application of computer methods for porosity measurements in sintered steels, Gingers and Metals R53/10 (2008) 628-645.
• [6] G. Matheron, Random sets of theory and its application to stereology, Journal of Microscopy (1972) 15-23.
• [7] A. Ciaś, M. Sułowski, J. Frydrych, The effect of variables on the porosity of P/M Mn steels, Proceedings of the International Conference “Powder Metallurgy and Particulate Materials” PM2TEC, Monteral, 2005, (CD-ROM).
• [8] A. Ciaś, S. Mitchell, A.S. Watts, Microstructure and mechanical properties of sintered (2–4)Mn–(0·6–0·8)C steels, Powder Metallurgy 42/3 (1999) 227-233.
• [9] S. Rutkowski, Design properties sintered products from powders and fibers, Scientific National Publisher, Warsaw, 1977, 228-231.
• [10] F.V. Lanel, Powder Metallurgy – Principles and Applications, MPIF, Princeton, New Jersey, 1980.
• [11] L.A. Dobrzański, M. Krupiński, B. Krupińska, Structure analysis of Al cast alloy, Journal of Achievements in Materials and Manufacturing Engineering 27/1 (2008) 23-26.
• [12] L.A. Dobrzański, J. Otręba, M.A. Grande, M. Rosso, Mechanical characteristic and mechanical properties of Ni- Mo-(W) steels, Journal of Achievements in Materials and Manufacturing Engineering 18 (2006) 347-350.
• [13] L.A. Dobrzański, Z. Brytan, M.A. Grande, M. Rosso, Corrosion resistance of sintered duplex stainless steels, Journal of Materials Processing Technology 192-193 (2007) 443-448. [14] M. Bilewicz, J.C. Viana, L.A. Dobrzański, Development of microstructure affected by in-mould manipulation in polymer composites and nanocomposite, Journal of Achievements in Materials and Manufacturing Engineering 31/1 (2008) 71-76.
• [15] L.A. Dobrzański, M. Bilewicz, J.C. Viana, A.M. Cunha, Non-conventionally obtained polymer nanocomposites at different nano-clay ratios, Journal of Achievements in Materials and Manufacturing Engineering 31/2 (2008) 9-14.