A shaped article can include a substrate formed from a glass material, a glass ceramic material, or a combination thereof and a cavity formed in the substrate. A sidewall of the cavity can have a random textured surface with a surface roughness of less than or equal to 300 nm. A method of machining a protrusion in a graphite block can include translating a cutting tool in a first longitudinal direction toward the graphite block to engage the graphite block with the cutting tool while rotating the cutting tool about a rotational axis without translating the cutting tool in a lateral direction, then translating the cutting tool in a second longitudinal direction away from the graphite block without translating the cutting tool in the lateral direction to disengage the cutting tool from the graphite block. A shaped article can be formed by pressing a preform with a monolithic graphite mold.

A system for machining an abradable material of a gas turbine engine and associated methods. The system includes a frame including a first arm extending from a central location. The system further includes an attachment structure coupled to the frame at the central location. Moreover, the attachment structure is configured to couple to at least a fan rotor of the gas turbine engine. Additionally, the system includes a cutting apparatus coupled to a first distal end of the first arm opposite the central location. The cutting apparatus includes a rotating shaft and plurality of cutting disks coupled to the rotating shaft. Further, the plurality of cutting disks define a helical cutting profile configured to machine a contour within the abradable material complementary to at least one fan blade of the gas turbine engine.

A system for machining an abradable material of a gas turbine engine and associated methods. The system includes a frame including a first arm extending from a central location. The system further includes an attachment structure coupled to the frame at the central location. Moreover, the attachment structure is configured to couple to at least a fan rotor of the gas turbine engine. Additionally, the system includes a cutting apparatus coupled to a first distal end of the first arm opposite the central location. The cutting apparatus includes a rotating shaft and plurality of cutting disks coupled to the rotating shaft. Further, the plurality of cutting disks define a helical cutting profile configured to machine a contour within the abradable material complementary to at least one fan blade of the gas turbine engine.

The present disclosure includes a protective tube for insertion into a pipe or vessel containing a medium, a measuring apparatus having such protective tube and to a method for producing the protective tube. The protective tube comprises a tubular member having a bore extending between an upper and lower end of the tubular member, and at least one helical fin formed on at least a section of an outer surface of the tubular member, winding around the outer surface of the tubular member and defining a flow channel along at least a part of the tubular member. An outer surface of the tubular member comprises a surface structure in an area of the at least one flow channel.

The present disclosure includes a protective tube for insertion into a pipe or vessel containing a medium, a measuring apparatus having such protective tube and to a method for producing the protective tube. The protective tube comprises a tubular member having a bore extending between an upper and lower end of the tubular member, and at least one helical fin formed on at least a section of an outer surface of the tubular member, winding around the outer surface of the tubular member and defining a flow channel along at least a part of the tubular member. An outer surface of the tubular member comprises a surface structure in an area of the at least one flow channel.

Disclosed is a helical milling tool with forward-backward feeding, the tool including a cutting portion, a neck portion and a handle portion, which are successively connected to each other; wherein the cutting portion includes a front-end cutting section, a circumferential cutting section and a back-end cutting section, which are connected successively to each other; the front-end cutting section is of an end milling cutter structure or a drill bit structure; the circumferential cutting section is of a cylindrical shape and is of a circumferential milling cutter structure; and the back-end cutting section is of a frustum-shaped. The tool can avoid defects such as layering and tearing, which go beyond processing requirements in a composite material, improve the processing quality, save on costs, simplify the processing process, improve the production efficiency and prolong the service life of the tool.

Disclosed is a method for helical milling with forward-backward feeding, including the following steps: determining the aperture D1 of a pre-processing hole; according to a final aperture D of a through-hole to-be-processed and the aperture D1 of the pre-processing hole, selecting a suitable tool; clamping the workpiece to-be-processed and the tool; the tool processes the pre-processing hole with forward feeding with aperture D1, D1<D, until the back-end cutting section of a cutting portion of the tool extends out of an outlet side; adjusting eccentricity of the tool one or more times, backward feeding from the outlet side, and using the back-end cutting section of the cutting portion of the tool to helical mill a through-hole with the aperture D. The present disclosure can avoid defects such as the delamination and tearing of a composite beyond processing requirements, improve the processing quality, save costs, simplify the processing process, increase the production efficiency of the tool and prolong the service life of the tool.

Disclosed is a method for helical milling with forward-backward feeding, including the following steps: determining the aperture D1 of a pre-processing hole; according to a final aperture D of a through-hole to-be-processed and the aperture D1 of the pre-processing hole, selecting a suitable tool; clamping the workpiece to-be-processed and the tool; the tool processes the pre-processing hole with forward feeding with aperture D1, D1<D, until the back-end cutting section of a cutting portion of the tool extends out of an outlet side; adjusting eccentricity of the tool one or more times, backward feeding from the outlet side, and using the back-end cutting section of the cutting portion of the tool to helical mill a through-hole with the aperture D. The present disclosure can avoid defects such as the delamination and tearing of a composite beyond processing requirements, improve the processing quality, save costs, simplify the processing process, increase the production efficiency of the tool and prolong the service life of the tool.

Machining ball tracks and guiding webs of an inner part for a constant velocity joint in a clamping arrangement includes mechanical machining of at least one first ball track in a first rotational position; rotating the articulated inner part into a second rotational position for machining at least one further ball track; wherein at least one guiding web is mechanically machined during the rotating of the inner joint part from the first rotational position into the second rotational position. A corresponding device is used for machining ball tracks and guiding webs of an inner joint part.

A machining center processes a section not to be corrected of a workpiece and a crankshaft bearing hole in a different position from the section not to be corrected and which is separated from an upper deck surface of the workpiece. The machining center supplies a coolant to the hole during processing and detects a temperature of the coolant. A control apparatus estimates the temperature of the coolant when a predetermined time elapses from a start of the processing to be a temperature of the workpiece, calculates a deformation amount of the workpiece due to thermal expansion, corrects a position of the hole with respect to the upper deck surface based on the deformation amount, and starts processing of the hole after the predetermined time. The predetermined time ends when a difference between a temperature near the hole and the temperature of the coolant falls within a predetermined range.