Abstract: A powder admixture useful for making a sintered engine part such as a valve seat insert includes a first iron-base powder and second iron-base powder wherein the first iron-base powder has a higher hardness than the second iron-base powder, the first iron-base powder including, in weight percent, 1-2% C, 10-25% Cr, 5-20% Mo, 15-25% Co, and 30-60% Fe, and the second iron-base powder including a vanadium-free tool steel powder such as a vanadium-free tool steel comprising, in weight %, 1-1.5% C, 3-15% Cr, 5-7% Mo, 3-6% W, and 60-85% Fe, the second iron-base powder further comprising vanadium carbide particles in an amount sufficient to reduce adhesive wear. The powder admixture can be sintered to form a sintered engine part optionally infiltrated with copper.

Abstract: An iron-based alloy includes, in weight percent, carbon from about 0.75 to about 2 percent; manganese from about 0.1 to about 1 percent; silicon from about 0.1 to about 1 percent; chromium from about 3 to about 6 percent; nickel up to about 4 percent; vanadium from about 1 to about 3 percent; molybdenum from about 4 to about 7 percent; tungsten from about 4 to about 7 percent; cobalt from about 4 to about 7 percent; boron up to about 0.1 percent; nitrogen from about 0.001 to about 0.15 percent, aluminum from about 0.001 to about 0.6 percent, copper from about 0.1 to about 1 percent, sulfur up to about 0.3 percent, phosphorus up to about 0.3 percent, up to about 5 percent total of tantalum, titanium, hafnium and zirconium; iron from about 65 to about 80 percent; and incidental impurities. The alloy is suitable for use in elevated temperature applications such as in valve seat inserts for combustion engines.

Abstract: An iron-based alloy includes, in weight percent, carbon from about 0.75 to about 2 percent; manganese from about 0.1 to about 1 percent; silicon from about 0.1 to about 1 percent; chromium from about 3 to about 6 percent; nickel up to about 4 percent; vanadium from about 1 to about 3 percent; molybdenum from about 4 to about 7 percent; tungsten from about 4 to about 7 percent; cobalt from about 4 to about 7 percent; boron up to about 0.1 percent; nitrogen from about 0.001 to about 0.15 percent, aluminum from about 0.001 to about 0.6 percent, copper from about 0.1 to about 1 percent, sulfur up to about 0.3 percent, phosphorus up to about 0.3 percent, up to about 5 percent total of tantalum, titanium, hafnium and zirconium; iron from about 65 to about 80 percent; and incidental impurities.

Abstract: A nickel-niobium intermetallic alloy contains, in weight percent, silicon from about 1.5 to about 3.5 percent; chromium from 5 to about 15 percent; nickel from about 45 to about 75 percent; niobium from about 14 to about 30 percent; cobalt up to about 7 percent; and iron up to about 10 percent; wherein the nickel plus niobium content is about 70 to about 90 percent and the total silicon, chromium, cobalt and iron content is about 10 to about 30 percent. The alloy can have a cast microstructure of at least 95 volume percent intermetallic phases and no more than about 5 volume percent solid solution phases. The intermetallic phases can include rod-like intermetallic phases of Ni3Nb and Ni8Nb7. The microstructure can be a lamellar microstructure and/or the microstructure can have less than 5 volume percent Ni—Fe and Ni—Co rich intermetallic phases.

Abstract: A powder admixture useful for making a sintered valve seat insert includes a first iron-base powder and second iron-base powder wherein the first iron-base powder has a higher hardness than the second iron-base powder, the first iron-base powder including, in weight percent, 1-2% C, 10-25% Cr, 5-20% Mo, 15-25% Co, and 30-60 wt. % Fe, and the second iron-base powder including, in weight %, 1-1.5% C, 3-15% Cr, 5-7% Mo, 3-6% W, 1-1.7% V, and 60-85% Fe. The powder admixture can be sintered to form a sintered valve seat insert optionally infiltrated with copper.

Abstract: An iron-based alloy includes, in weight percent, carbon from about 0.75 to about 2 percent; manganese from about 0.1 to about 1 percent; silicon from about 0.1 to about 1 percent; chromium from about 3 to about 6 percent; nickel up to about 4 percent; vanadium from about 1 to about 3 percent; molybdenum from about 4 to about 7 percent; tungsten from about 4 to about 7 percent; cobalt from about 4 to about 7 percent; boron up to about 0.1 percent; nitrogen from about 0.001 to about 0.15 percent, aluminum from about 0.001 to about 0.6 percent, copper from about 0.1 to about 1 percent, sulfur up to about 0.3 percent, phosphorus up to about 0.3 percent, up to about 5 percent total of tantalum, titanium, hafnium and zirconium; iron from about 65 to about 80 percent; and incidental impurities. The alloy is suitable for use in elevated temperature applications such as in valve seat inserts for combustion engines.

Abstract: A cobalt-rich wear resistant and corrosion resistant alloy useful for parts of a combustion engine such as valve seat inserts includes, in weight % about 0.1 to about 0.8% C, about 0.1 to about 1.5% Mn, about 3 to about 5% Si, about 10 to about 20% Cr, about 5 to about 32% Fe, about 0.5 to about 4% W, about 10 to about 30% Mo, up to about 20% Ni, about 20 to about 40% Co, up to about 6% V, up to about 3% Nb, total V plus Nb of about 0.5 to about 8.5% and balance unavoidable impurities including up to 0.035% P, up to 0.015% S and up to 0.250% N.

Abstract: A cobalt-rich wear resistant and corrosion resistant alloy useful for parts of a combustion engine such as valve seat inserts includes, in weight % about 0.1 to about 0.8% C, about 0.1 to about 1.5% Mn, about 3 to about 5% Si, about 10 to about 20% Cr, about 5 to about 32% Fe, about 0.5 to about 4% W, about 10 to about 30% Mo, up to about 20% Ni, about 20 to about 40% Co, up to about 6% V, up to about 3% Nb, total V plus Nb of about 0.5 to about 8.5% and balance unavoidable impurities including up to 0.035% P, up to 0.015% S and up to 0.250% N.

Abstract: A method of casting valve seat inserts comprises pouring molten metal into a gating system of a mold plate stack wherein mold plates are located between top and bottom molds wherein the gating system includes a casting header, down-sprue, horizontal sprue, up-sprues, runners, and gates in fluid communication with mold cavities configured to form the valve seat inserts. The method includes filling the mold cavities with the molten metal, and controlling solidification of the molten metal in the mold cavities by means of an outer thermal barrier which retards heat transfer in mold plate material between the mold cavities and an outer periphery of the mold plate stack. An inner thermal barrier can be used to further control solidification of the molten metal. Valve seat inserts produced using the thermal jacket molds can exhibit an improved microhardness distribution which provides improved machining and higher yield.

Abstract: A method of casting valve seat inserts comprises pouring molten metal into a gating system of a mold plate stack wherein mold plates are located between top and bottom molds wherein the gating system includes a casting header, down-sprue, horizontal sprue, up-sprues, runners, and gates in fluid communication with mold cavities configured to form the valve seat inserts. The method includes filling the mold cavities with the molten metal, and controlling solidification of the molten metal in the mold cavities by means of an outer thermal barrier which retards heat transfer in mold plate material between the mold cavities and an outer periphery of the mold plate stack. An inner thermal barrier can be sued to further control solidification of the molten metal. Valve seat inserts produced using the thermal jacket molds can exhibit an improved microhardness distribution which provides improved machining and higher yield.

Abstract: An iron-based corrosion resistant and wear resistant alloy includes (in weight percentage) carbon from about 1.6 to 3%, silicon from about 0.8 to 2.1%, manganese up to 1.0%, chromium from about 12.0 to 15.0%, molybdenum from about 2.0 to 4.0%, nickel from about 0.2 to 0.8%, copper up to 4.0%, boron up to 0.5%, and the balance including iron and incidental impurities. The alloy is suitable for use in elevated temperature applications such as in valve seat inserts for combustion engines.

Abstract: An iron-based corrosion resistant and wear resistant alloy includes (in weight percentage) carbon from about 1.6 to 3%, silicon from about 0.8 to 2.1%, manganese up to 1.0%, chromium from about 12.0 to 15.0%, molybdenum from about 2.0 to 4.0%, nickel from about 0.2 to 0.8%, copper up to 4.0%, boron up to 0.5%, and the balance including iron and incidental impurities. The alloy is suitable for use in elevated temperature applications such as in valve seat inserts for combustion engines.