Santrade, Ltd

Sandvik Aktiebolag

Battelle Memorial Institute

Carl S Ekemar

Rolf G Oskarsson

Gunnar Brandt

Herbert Schachner

Bengt O Haglund

Carl P Bjorkman

Ulf E Jutterstrom

Per I Andersson

The present invention relates to powder particles consisting of hard principles and binder metal for the manufacture of superior, uniquely fine-grained hard material alloys and to a procedure for the preparation of said particles. The preparation is performed in an economical way because the procedure starts from conventional melt metallurgical raw materials. A pre-alloy consisting of hard principle forming and binder phase forming elements is subjected to a heat treatment such as nitriding and carburizing after being crushed. The final product is particles composed by hard principle phases and binder metal phases formed 'in situ' in an effective binding.

Powder particles for fine-grained hard material alloys and a process for

Powder particles for fine-grained hard material alloys

The present invention relates to a unique and advantageous method making possible a superior technical and economical separation of cemented carbide bodies based upon their compositions and structures. The critical point of the method is, that after formation of a melt by melting of the binder metal including dissolved elements from the hard constituents there are so strong driving forces dependent on the grain size variables, proportions and compositions of the hard constituent phases, that melt is re-distributed between cemented carbide bodies in communicating contact. The re-distribution is determined by differences of mean grain sizes, grain size distributions, relative proportions and compositions of the hard constituent phases of the bodies.

Method of treating cemented carbide bodies regarding their compositions

Process for the preparation of molybdenum-tungsten carbides

Ceramic materials intended for cutting and consisting of aluminum oxide with additives of hard carbides or nitrides, particularly titanium carbide, have up to now, because of their sintering inertia, in general been pressure sintered to obtain satisfactory properties. According to the present invention a ceramic alloy of excellent technological properties has been formed and comprises principally Al.sub.2 O.sub.3 and hard nitrides or carbonitrides, such as TiN or Ti(C,N) in which the alloy contains from 2 to 95 v/o of an Al--O--N-compound, such as nitrogen stabilized aluminum oxide with cubic or nearly cubic structure.

Ceramic alloy

The alloy of the invention is of the type wherein 30-70% by volume of hard components are homogeneously dispersed in a matrix of binder metal (Fe, Co or Ni). The hard components are carbides or carbonitrides and/or borides of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and/or W. The mean grain size of the hard component particles is between 0.01 and 1.0 micron and their grain size distribution, represented by the standard deviation S, in which S.sup.2 .ltoreq.(M/1+1.5 M.sup.z).sup.2 .mu.m.sup.2, not more than 15% of the grains are larger than 1.2 microns.

Wear resistant alloy

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Saltsjo-Boo, Sweden

Carl S Ekemar