A cutting tool according to the present disclosure has a rake face, a flank face, and a cutting edge. The cutting edge is located between the rake face and the flank face. The cutting tool includes a substrate composed of a cubic boron nitride sintered material, and an oxide layer that covers the substrate and that constitutes at least part or whole of the rake face, the flank face, and the cutting edge. The oxide layer includes at least one element selected from a group consisting of titanium, aluminum, zirconium, and cobalt. A thickness of the oxide layer is 2 μm or less.

A cutting tool including a rake face, a flank face, and a cutting edge portion, comprising a substrate and an AlTiN layer, the AlTiN layer including cubic Al.sub.xTi.sub.1-xN crystal grains, Al having an atomic ratio x of 0.7 or more and 0.95 or less, the AlTiN layer including a central portion, the central portion at the rake face being occupied in area by (200) oriented crystal grains at a ratio of 80% or more, the central portion at the flank face being occupied in area by (200) oriented crystal grains at a ratio of 80% or more, the central portion at the cutting edge portion being occupied in area by (200) oriented crystal grains at a ratio of 80% or more.

A surface-coated cutting tool includes a substrate and a coating film. The coating film includes an alternate layer. The alternate layer includes a first layer having a first composition and a second layer having a second composition. The alternate layer is formed by alternately stacking at least one first layer and at least one second layer. The first layer and the second layer each have a thickness not smaller than 2 nm and not greater than 100 nm. The first composition is expressed as Ti.sub.aAl.sub.bSi.sub.cN (0.25≤a≤0.45, 0.55≤b≤0.75, 0≤c≤0.1, a+b+c=1). The second composition is expressed as Ti.sub.dAl.sub.eSi.sub.fN (0.35≤d≤0.55, 0.45≤e≤0.65, 0≤f≤0.1, d+e+f=1). The first composition and the second composition satisfy a condition of 0.05≤d−a≤0.2 and 0.05≤b−e≤0.2.

A coated tool may include a base member and a coating layer located on the base member. The coating layer may include a plurality of AlTi layers including aluminum and titanium as a main component, and a plurality of AlCr layers including aluminum and chromium as a main component. The AlTi layers and the AlCr layers may be located alternately one upon another. The plurality of AlTi layers may include a first AlTi layer and a second AlTi layer located farther away from the base member than the first AlTi layer. Each of the plurality of AlTi layers may further include chromium, and a content ratio of chromium in the second AlTi layer may be higher than a content ratio of chromium in the first AlTi layer.

A lubricant material for assisting machining process comprising fullerene.

A device for machining a work piece creates an electrical potential between an electrode and the work piece or another conducting body proximate to the work piece. The electrical potential establishes an electrical field within the work piece that is expected to repel electrons and create a region of positively charged ions which repel one another. This region is expected to be weakened and material is expected to be removable from this region of the work piece using less force and energy than when machined by traditional machining techniques.

Provided is a cutting tool including a base material and a coating layer provided on the base material, the coating layer including a titanium carbonitride layer provided on the base material, an intermediate layer provided on the titanium carbonitride layer in contact therewith, and an alumina layer provided on the intermediate layer in contact therewith, the intermediate layer being composed of a compound made of titanium, carbon, oxygen, and nitrogen, the intermediate layer having a thickness of more than 1 μm, when P.sub.N1 atomic % represents an atomic ratio of the nitrogen in an interface between the intermediate layer and the alumina layer, and P.sub.N2 atomic % represents an atomic ratio of the nitrogen at a point A away from the interface by 1 μm on a side of the intermediate layer, a ratio P.sub.N1/P.sub.N2 of the P.sub.N1 to the P.sub.N2 being more than or equal to 1.03.

The use of cryogenic coolant in a machining operation in Ti, Ti-alloys or Ni-alloys together with a cutting tool of a cemented carbide substrate with a gradient surface zone with a thickness of between 50-400 μm is provided. The cemented carbide substrate has a binder phase gradient with the lowest binder phase content in the outermost part of the gradient surface zone and the cemented carbide having graphite. The arrangement leads to a significantly prolonged tool life.

A cemented carbide cutting tool having WC and a low amount of binder phase can be used when machining Ti, Ti-alloys and Ni-based alloys under cryogenic conditions, leading to a significantly prolonged tool life.

A coated tool may include a base member including a first surface and a coating layer located on the base member. The coating layer may include a first layer, a second layer, and a plurality of voids. In an inclination angle distribution graph in which an inclination angle formed by a normal line of a {112} surface that is a crystal surface of crystal grains of the first layer with respect to a normal line of a surface of the first layer is measured, the measured inclination angles within a range of 0 to 45° are divided into pitches of 0.25°, and degrees existing in each division are accumulated, the highest peak exists in a range of 0 to 10°. The total number of degrees existing within this range accounts for 45% or more of all degrees.