Inventors:
Stanislaw Mocarski - Toronto, CA
Charles Oliver Mchugh - Dearborn Heights MI
Russell A. Chernenkoff - Livonia MI
David Alan Yeager - Plymouth MI
Assignee:
Ford Global Technologies, Inc. - Dearborn MI
International Classification:
B22F 312
C22C 3302
Abstract:
A method of making a structural iron-based article comprising: (a) blending a compressible base iron powder (max. particle size of 100 microns) a graphite powder to provide carbon in mixture, and a single master alloy powder (average particle size of 10 microns) meltable within the range of 900. degree. -1200. degree. C. (1690. degree. -2220. degree. F. ) to form a mixture, the master alloy powder being present in an amount of 1-5% by weight of the mixture and consisting of (i) hardenability enhancing alloying ingredients selected from Mn, Mo, Ni, Cr, Cu and Fe, with Fe being present only if Cr or Mo is selected and (ii) wetting agents selected from the group of B, Y, Si and rare earth misch metal, the master alloy being devoid of carbon and being proportioned to provide a desired amount of hardenability in the base powder; (b) compacting the mixture to a green density 7. 1-7. 4 g/cm. sup. 3 to form a green part (c) machining the green part to a desired configuration if necessary; (d) sintering the green part to achieve liquification of the master alloy to densify the part to 7. 3-7. 5 g/cm. sup. 3 without substantially varying the configuration of the green; and (e) cooling the sintered part at a controlled rate to form a desired microstructure such as essentially a bainite or ferrite/pearlite microstructure.