Abstract: A cutting tool insert includes a cemented carbide substrate and a coating. The cemented carbide substrate comprises WC, 4-7 wt % cobalt, 6-9 wt % cubic carbide forming metals from the groups IVB and VB, preferably titanium, tantalum and niobium, with a binder phase enriched surface zone with a thickness of >20 ?m, preferably between 21 and 50 ?m. The coating comprises a first layer adjacent the cemented carbide substrate of Ti(C,N) having a thickness of from about 3 to about 15 ?m, an alumina layer adjacent said first layer having a thickness of from about 3 to about 15 ?m, said alumina layer being composed of ?-Al2O3, a further layer adjacent the alumina layer of a Ti(C,N) or Ti(C,O,N) having a thickness of from about 1 to 10 ?m. The total thickness of the coating being less than 30 ?m, preferably less than 20 ?m. Inserts according to the invention exhibit favourable wear resistance and edge strength when turning steel.

Abstract: The invention relates to a method of making cemented carbides having surfaces free free of detrimental binder phase layer. This is achieved by the inclusion of controlled amounts of carbonitride in the carbide composition. The invention also relates to the cemented carbides so formed.

Abstract: A cutting tool insert includes a cemented carbide substrate and a coating. The cemented carbide substrate comprises WC, 4-7 wt % cobalt, 6-9 wt % cubic carbide forming metals from the groups IVB and VB, preferably titanium, tantalum and niobium, with a binder phase enriched surface zone with a thickness of >20 ?m, preferably between 21 and 50 ?m. The coating comprises a first layer adjacent the cemented carbide substrate of Ti(C,N) having a thickness of from about 3 to about 15 ?m, an alumina layer adjacent said first layer having a thickness of from about 3 to about 15 ?m, said alumina layer being composed of ?-Al2O3, a further layer adjacent the alumina layer of a Ti(C,N) or Ti(C,O,N) having a thickness of from about 1 to 10 ?m. The total thickness of the coating being less than 30 ?m, preferably less than 20 ?m. Inserts according to the invention exhibit favourable wear resistance and edge strength when turning steel.

Abstract: A cutting tool insert includes a cemented carbide substrate and a coating. The cemented carbide substrate comprises WC, 4–7 wt % cobalt, 6–9 wt % cubic carbide forming metals from the groups IVB and VB, preferably titanium, tantalum and niobium, with a binder phase enriched surface zone with a thickness of >20 ?m, preferably between 21 and 50 ?m. The coating comprises a first layer adjacent the cemented carbide substrate of Ti(C,N) having a thickness of from about 3 to about 15 ?m, an alumina layer adjacent said first layer having a thickness of from about 3 to about 15 ?m, said alumina layer being composed of ?-Al2O3, a further layer adjacent the alumina layer of a Ti(C,N) or Ti(C,O,N) having a thickness of from about 1 to 10 ?m. The total thickness of the coating being less than 30 ?m, preferably less than 20 ?m. Inserts according to the invention exhibit favourable wear resistance and edge strength when turning steel.

Abstract: The invention relates to a method of making cemented carbides having surfaces free free of detrimental binder phase layer. This is achieved by the inclusion of controlled amounts of carbonitride in the carbide composition. The invention also relates to the cemented carbides so formed.

Abstract: A cutting tool insert includes a cemented carbide substrate and a coating. The cemented carbide substrate comprises WC, 4-7 wt % cobalt, 6-9 wt % cubic carbide forming metals from the groups IVB and VB, preferably titanium, tantalum and niobium, with a binder phase enriched surface zone with a thickness of >20 &mgr;m, preferably between 21 and 50 &mgr;m. The coating comprises a first layer adjacent the cemented carbide substrate of Ti(C,N) having a thickness of from about 3 to about 15 &mgr;m, an alumina layer adjacent said first layer having a thickness of from about 3 to about 15 &mgr;m, said alumina layer being composed of &agr;-Al2O3, a further layer adjacent the alumina layer of a Ti(C,N) or Ti(C,O,N) having a thickness of from about 1 to 10 &mgr;m. The total thickness of the coating being less than 30 &mgr;m, preferably less than 20 &mgr;m. Inserts according to the invention exhibit favourable wear resistance and edge strength when turning steel.

Abstract: A cutting tool insert particularly useful for wet and dry milling of low and medium alloyed steels and stainless steels includes a cemented carbide body with a coating consisting of an MTCVD Ti(C,N) layer and a multi-layer coating being composed of &kgr;-Al2O3 and TiN or Ti(C,N) layers.