摘要:
A pitch densification apparatus may be used to form a carbon-carbon composite material. In some examples, the apparatus is configured to pitch densify a material using one or more of a plurality of different pitch densification techniques. For example, the apparatus may densify a material with a selectable one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, and/or the vacuum pressure infiltration cycle. The apparatus may respond to initial or changing properties of a material to be densified. In some additional examples, the apparatus includes a mold configured to receive a preform and a portion of solid pitch separate from the preform. The apparatus may include a heating source thermally coupled to the mold that is configured to heat the solid pitch above a melting temperature of the solid pitch. The apparatus may melt the pitch without external pitch melting equipment.
摘要:
A pitch densification apparatus may be used to form a carbon-carbon composite material. The apparatus may be used to compress a carbon fiber material, and, thereafter, pitch densify the carbon fiber material. The compression and pitch densification of the carbon fiber material may be carried out within the same mold cavity of the pitch densification apparatus. In one example, an apparatus may comprise a mold defining a mold cavity that is configured to receive a material to be densified. The mold cavity is configured to be adjusted from a first volume to a second volume less than the first volume to compress the material in the mold cavity. The example apparatus may further comprise a gas source configured to apply a gas pressure in the mold cavity to force pitch into the material in the mold cavity to densify the material, and a vacuum source configured to create a vacuum pressure in the mold cavity at least prior to the application of the gas pressure.
摘要:
A method of manufacturing a carbon-carbon brake disc uses a restraint fixture (12) that includes a preform retention region configured to limit contracting forces applied against a preform (10) in the preform retention region when the restraint fixture (12) thermally contracts. In one embodiment, the restraint fixture (12) comprises a band (12) having a first surface defining the preform retention region and a first expansion portion (26, 28, 29) adapted to deform upon application of a force to the band (12).
摘要:
It is an object to provide the manufacturing method for the friction material (4) which maintains the quality of the friction material (4) and reduces the cost of the facilities and the maintenance cost. The manufacturing method for a friction material (4) comprising a molding step of the friction material (4) as pressurizing and heating a molding material made of a raw friction material within a molding die with an upper die (1), a middle die (2), and a lower die (3), wherein a temperature of the upper die (1) and the lower die (3) in said molding step is 190° C.-230° C. and a pressure thereof is 0.05 MP-10 MP.
摘要:
The invention relates to a method for producing ceramic brake discs, comprising the following steps: a) producing a BMC compound (2) with a matrix consisting of phenol resin and with carbon reinforcement fibres, the length of the carbon fibres being between 6 mm and 50 mm; b) poducing a green compact of the ceramic brake discs from the BMC compound (2) in a transfer moulding or injection compression moulding process, c) pyrolysing the green compact in order to produce a porous moulded body; and d) melt-infiltrating the porous moulded body with a melt, preferably a silicon melt, in order to produce a moulded body with reaction-bonded fibers.
摘要:
The invention relates to the field of forming fibrous structures by needling processes. A process is provided for achieving a desired Z-fiber distribution in a fibrous structure by controlling transport depth during formation of the fibrous structure in a series of needling passes. Each needling pass generates a portion of Z-fiber bundles that penetrate adjacent fibrous layers, the Z-fiber bundles penetrating only those adjacent fibrous layers that need more Z-fiber bundles to attain a predetermined number of Z-fiber bundles within each fibrous layer.
摘要:
The invention relates to the field of needling processes for forming fibrous preform structures. The invention is particularly useful in forming fibrous preform structures suitable for subsequent processing into high temperature resistant composite structures such as carbon/carbon aircraft brake disks. The process according to the invention compensates for fiber pull back induced by fiber resilience, and for compaction in previously needled layers induced during subsequent needling passes. According to a further aspect of the invention, Z-fiber distribution throughout the thickness of the fibrous preform structure may be manipulated as necessary to achieve a desired distribution.
摘要:
In a process of manufacturing a substrate provided with a synthetic resin-bonded friction coating, the friction coating, which is joined to the substrate by a primer is formed in that a powder mixture which contains a friction powder and a synthetic resin powder is compacted and is cured at an elevated temperature.To eliminate the need for precompacting the powder mixture before it is applied to the substrate, said powder mixture is applied to the substrate to form a powder layer which can be compacted to the desired thickness of the friction coating. The powder layer which has been applied is then heated for a short time before the powder layer is compacted to the desired thickness of the friction coating.
摘要:
An improved brake shoe assembly is provided wherein friction material is cast directly onto a brake liner plate. The brake liner includes a plurality of perforations which form protruding tabs. Interengagement between the cast friction material and the perforated areas and tabs provides excellent interlocking strength between these components. The number, size, orientation and configuration of these tabs may be selected with regard to the specific operating characteristics to which the brake shoe assembly is to be employed.
摘要:
A heated brake shoe press has a longitudinal open end cavity defined by a base and cover. One end of the cavity may be closed by a movable platen. A movable plunger projects into the other end of the cavity and is slideably engaged with the cavity throughout its length. Inserts and liners are slideably engaged in the cavity in a given order and define a plurality of molding cavities that are fillable with moldable material. The heat, and the pressure exerted by the plunger configures the material in the molding cavities to a shape defined by the inserts and liners. After forming, the platen may be moved to an open position and the inserts and configured material may be pushed out of the cavity by the plunger. To accommodate such action and to reduce galling and scoring of the cavity walls, Teflon buttons are attached to the insert faces which engage the cavity wall.