Sintered material
AssigneeBrico Engineering Limited
InventorsCharles G. Purnell, Paritosh Maulik
Life of this patent
Estimating the term…
Abstract
Sintered materials and a method for their manufacture are described together with products made therefrom, such as piston rings and valve seat inserts for internal combustion engines. The sintered material comprises a porous matrix with a composition lying in the range expressed in wt % of 8 to 12 chromium, 0.5 to 3 molybdenum, up to 1.5 vanadium, 0.2 to 1.5 carbon, other impurities 2 max., up to 1 manganese sulphide, optionally up to 5 molybdenum disulphide, balance iron, the matrix having a uniform dispersion of submicroscopic particles of molybdenum rich carbides which render the material resistant to thermal softening.
Claims24
A sintered ferrous material which has a porous molybdenum/chrominum martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum-rich carbides less than 1 micron in size substantially uniformly distributed therein.
A sintered ferrous material which has a porous molybdenum/chromium martensitic matrix formed from a single alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the matrix having sub-microscopic molybdenum rich carbides less than 1 micron in size substantially uniformly distributed therein, the matrix being infiltrated with copper or a copper based alloy.
A sintered ferrous material which has a porous matrix having a recticular structure of essentially two phases, a first phase formed from an alloy having a composition expressed in weight percent consisting essentially of 8-12 chromium, 0.5-3 molybdenum, up to 1.5 vanadium, 0.2-1.5 carbon, other impurities 2 max, and the balance iron, the first phase having sub-microscopic molybdenum-rich carbides less than 1 micron, in size substantially uniformly distributed therein, and a second phase of pearlite with some residual ferrite regions formed from a relatively pure iron powder with carbon addition, the two phases having transition zones therebetween, the transition zones comprising martensite and bainite.
Dependencies are inferred from the claim text.