Abstract: A cermet has a hard phase which contains W and nitrogen, and includes at least one selected from a carbide, nitride and carbonitride of a metal having Ti as a main component, and a binder phase having an iron group metal as a main component. A W amount contained in the whole cermet is 5 to 40% by weight, an interfacial phase including a complex carbonitride with a larger W amount than a W amount of the hard phase being present between grains of the hard phase, and when a W amount contained in the interfacial phase based on the whole metal element is represented by Wb (atomic %), and a W amount contained in the hard phase based on the whole metal element is represented by Wh (atomic %), then, an atomic ratio of Wb to Wh (Wb/Wh) is 1.7 or more. The cermet is excellent in fracture resistance and wear resistance.

Abstract: A cermet has a WC first hard phase, a second hard phase including one or more of a carbide, nitride and carbonitride of an element(s) of groups 4, 5 and 6 of the Periodic Table including a titanium element, and a mutual solid solution thereof, and a binder phase. In the cermet, a carbon amount CT (% by weight), a tungsten amount CW (% by weight), and a nitrogen amount CN (% by weight) satisfy 0.25<(CN/(CT?0.0653·CW))<6. The cermet has a surface region with a thickness of 5 to 100 ?m which includes the first hard phase and the binder phase, and an inner region which includes the first and second hard phases and the binder phase. In a cross-section of the inner region, a ratio of an area of the first hard phase to an area of the second hard phase is 0.15 to 4.

Abstract: A cermet has a hard phase which contains W and nitrogen, and includes at least one selected from a carbide, nitride and carbonitride of a metal having Ti as a main component, and a binder phase having an iron group metal as a main component. A W amount contained in the whole cermet is 5 to 40% by weight, an interfacial phase including a complex carbonitride with a larger W amount than a W amount of the hard phase being present between grains of the hard phase, and when a W amount contained in the interfacial phase based on the whole metal element is represented by Wb (atomic %), and a W amount contained in the hard phase based on the whole metal element is represented by Wh (atomic %), then, an atomic ratio of Wb to Wh (Wb/Wh) is 1.7 or more. The cermet is excellent in fracture resistance and wear resistance.

Abstract: A hard powder contains much amount of a complex carbonitride solid solution, which can improve sinterability of a sintered hard alloy and give a uniform structure. The hard powder is a powder containing 90 vol % or more of a complex carbonitride solid solution represented by (Ti1-x,Mx)(C1-y,Ny), wherein M represents at least one element selected from the group consisting of W, Mo, Nb, Zr and Ta, x represents an atomic ratio of M based on the sum of Ti and M, y represents an atomic ratio of N based on the sum of C and N, x and y satisfy 0.05?x?0.5 and 0.01?y?0.75.

Abstract: There are disclosed a surface refined sintered alloy body which comprises a hard phase containing at least one selected from the group consissting of carbides, carbonitrides, carbooxides, carbonitrooxides of the metals of the groups 4a, 5a and 6a of the periodic table and a binding phase containing at least one selected from iron group metals, characterized in that the concentration of the binding phase in the surface layer (of from 10 .mu.m to 500 .mu.m from the surface of the sintered alloy) is highest at the outermost surface thereof and approaches the concentration of the inner portion, the concentration of the binding phase decreasing from the outermost surface to a point at least 5 .mu.m from the surface; and a method for making the same by applying decarburization treatment at the surface of the sintered alloy at temperatures within the solid-liquid co-existing region of the binding phase after sintering or in the process of sintering.