A method and system for drilling holes in a repaired composite structure. Four corner holes are selected from holes outside of a repaired area in the repaired composite structure. The four corner holes define a rectangle encompassing the repaired area with sides that each include a pair of corner holes with intermediate holes in between. A surface representation is generated based on a scan of the repaired composite structure that includes the rectangle. Side hole locations between a corresponding pair of corner holes are generated for each side of the rectangle. Grid vector lines are generated between corresponding pairs of side hole locations on opposite sides of the rectangle. The grid vector lines intersect each other at intersection points on the surface representation. Point coordinates are determined for intersection points that lie within the repaired area. A path is created for drilling holes at point coordinates for the intersection points.

Described herein is a first method of forming a hole in a workpiece, having a first surface and a second surface opposite the first surface. The method includes forming a first hole, having a first diameter, in the workpiece by passing a first cutter through the workpiece from the first surface to the second surface. Additionally, the method includes forming a chamfer in the second surface of the workpiece concentric with the first hole using a second cutter. The chamfer has a second diameter larger than the first diameter. The method further includes forming a second hole, having a third diameter larger than the first diameter, in the workpiece concentric with the first hole by passing a third cutter through the workpiece from the first surface to the second surface.

A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and non-diamond carbon dispersed in the polycrystalline diamond, and has a concentration of contained hydrogen of greater than 1000 ppm and less than or equal to 20000 ppm.

A method for processing a CMC airfoil includes nesting an airfoil fiber preform in a cavity of a fixture that has first and second tool segments, closing the fixture by rotating a first tool segment about a hinge, the closing causing the tool segments to clamp on a tail portion of the fiber preform and thereby conform the tail portion to the fixture. While in the fixture, the fiber preform is then partially densified with an interface coating material to form a partially densified fiber preform. While still in the fixture, one or more cooling holes are drilled into the trailing edge of the partially densified fiber preform. After the drilling, the partially densified fiber preform is removed from the fixture and further densified with a ceramic matrix material to form a fully densified CMC airfoil.

A cutting tool for performing cutting operations on a workpiece when the cutting tool is rotated about a central axis by a machine tool, the cutting tool includes a generally cylindrical body disposed about the central axis. The generally cylindrical body includes a first end and an opposite second end. The cutting tool further includes a cutting portion and a mounting portion. The cutting portion is disposed at or about the first end of the generally cylindrical body and includes a number of cutting edges structured to engage the workpiece during cutting operations. The mounting portion is disposed at or about the opposite second end of the generally cylindrical body and is structured to be coupled to the machine tool. At least a portion of the generally cylindrical body comprises a molded portion formed via a molding process about the cutting portion in a manner that couples the cutting portion to the generally cylindrical body.

A pipe lathe includes a shaft; a cutting head supported on the shaft for movement with the shaft; a mandrel positionable on an outboard end of the shaft for supporting the shaft along a machining axis; and a first external pipe clamp and a second external pipe clamp, the first and the second external pipe clamps supported for external pipe engagement substantially concentrically about the machining axis. Multiple spaced apart engagement sites provided by the mandrel within the pipe and the external pipe clamps on an outer surface of the pipe support the pipe in a linear and centered position for machining by the cutting head, even when the pipe is non-linear, flexible and possibly with a cross section that is on-circular.

A cutting tool comprising a base material and a coating, wherein the coating comprises a hard particle layer, the hard particle comprises a multilayer structure in which a first unit layer formed from a first compound and a second unit layer from a second compound are alternately stacked, each of the first compound and the second compound consists of one or more metal elements selected from the group consisting of a periodic table group 4 element, a periodic table group 5 element, and a periodic table group 6 element, silicon, and one or more elements selected from the group consisting of carbon, nitrogen, boron, and oxygen, and a percentage of the number of atoms of the silicon to a sum of the numbers of atoms of the metal element and the silicon in the first unit layer is different from that in the second unit layer.

The illustrative embodiment of the present invention uses a tangible three-dimensional structure as a fiducial mark, which structure is, at least partially, tolerant of dimensional variations in the article. The illustrative embodiment uses three such tangible three-dimensional structures: (1) a portion of a tangible conical surface, (2) a portion of a tangible spheroidal surface, and (3) a portion of a tangible pyramidal surface.

A method for processing a CMC airfoil includes nesting an airfoil fiber preform in a cavity of a fixture that has first and second tool segments, closing the fixture by rotating a first tool segment about a hinge, the closing causing the tool segments to clamp on a tail portion of the fiber preform and thereby conform the tail portion to the fixture. While in the fixture, the fiber preform is then partially densified with an interface coating material to form a partially densified fiber preform. While still in the fixture, one or more cooling holes are drilled into the trailing edge of the partially densified fiber preform. After the drilling, the partially densified fiber preform is removed from the fixture and further densified with a ceramic matrix material to form a fully densified CMC airfoil.

A drilling apparatus and method for drilling holes into a composite workpiece. The drilling apparatus may include an end effector, a drill bit, and a control system. The end effector may include an end effector housing, a drill bit attachment, a rotation actuator, and a linear motion actuator. The linear motion actuator may convert rotary motion of a rotary motor into linear motion of the drill bit attachment. The drill bit may have a widest portion which cuts a hole into the workpiece and a narrow flute portion limiting contact time between the drill bit and the workpiece. The control system may control a speed of the linear motion actuator, with a first speed as the drill bit is plunged into the workpiece and a second speed, slower than the first speed, as the drill bit is retracted out of the workpiece.