摘要:
Pistons reciprocating in cylinders of a hydrocarbon-fueled internal combustion engine tend to trap air and unburned fuel between the top of the piston head and its enclosing cylinder wall. The circumferential side surface (or land) of the piston head above its upper piston ring groove is provided with a thin coating of porous aluminum oxide. Particles of an oxidation catalyst for the engine's fuel are electrolytically deposited in the pores of the oxide coating. During engine operation the oxide-supported catalyst particles promote combustion of the entrained fuel.
摘要:
A method for the color finishing of aluminum frames and other components for motor vehicles comprises anodizing an aluminum surface and coloring the aluminum surface. The coloring of the aluminum surface may be effected by an adsorptive coloring process, an electrolytic coloring process, an interference coloring process, or any combination of the foregoing processes.
摘要:
Durable elastomeric polyurea coatings can be applied to metal surfaces subjected to impacts and environmental corrosion. Corrosion resistance of the coatings, especially on magnesium alloy surfaces, is improved by incorporation of particulate inhibitor additives in the liquid polyurea precursor coating material. Examples of inhibitors include potassium dichromate, sodium dichromate, potassium permanganate, vanadium pentoxide, phosphorus anhydride, cerium oxide, lanthanum oxide, calcium oxide and sodium oxide.
摘要:
Die casting of some magnesium alloys may yield castings that are susceptible to corrosion when exposed to salt water or other aggressive oxidizing environments. Such corrosion may result from the existence of different microstructures in a cross-section of the die casting (e.g. between the surface of the part and the center) that produce galvanic couples that are susceptible to such corrosive attack. However, a die temperature may be determined for casting of the part such that a more uniform cross-sectional microstructure is produced in which minimal or negligible galvanic potentials are produced.
摘要:
Mold tooling formed of suitable iron-nickel alloys and provided with a hard electroless nickel coating on the mold cavity surface are useful for high volume production of carbon fiber reinforced, polymer matrix, composites. The iron and nickel alloy provides thermal expansion properties for the molding of dimensionally accurate parts. The nickel alloy coating provides a durable surface, without adversely affecting the expansion properties of the mold, and remains adherent to the base metal during the repeated thermal cycling encountered in high volume production of substantially identical molded carbon composite parts.
摘要:
A valve for an anti-lock brake system, wherein the anti-lock brake system is configured for controlling flow of a fluid, includes a housing defining a cavity therein and having a longitudinal axis, a valve seat disposed within the cavity so as to define a first passage for the fluid, and an armature disposed within the cavity so as to at least partially define a second passage for the fluid. The armature is translatable with respect to the valve seat along the longitudinal axis and matable with the valve seat to seal off fluid communication between the first passage and the second passage. The armature defines a surface that is substantially resistant to corrosion from the fluid, and the surface is substantially free from a coating including zinc.
摘要:
A valve for an anti-lock brake system, wherein the anti-lock brake system is configured for controlling flow of a fluid, includes a housing defining a cavity therein and having a longitudinal axis, a valve seat disposed within the cavity so as to define a first passage for the fluid, and an armature disposed within the cavity so as to at least partially define a second passage for the fluid. The armature is translatable with respect to the valve seat along the longitudinal axis and matable with the valve seat to seal off fluid communication between the first passage and the second passage. The armature defines a surface that is substantially resistant to corrosion from the fluid, and the surface is substantially free from a coating including zinc.
摘要:
A method is disclosed for high volume production of molded dimensionally accurate polymer composite articles comprising three-dimensional carbon fiber reinforcement in high volume. Carbon fiber cloth infiltrated with a liquid thermosetting polymer precursor is shaped by application of pressure to urge the cloth against the surface of a mold and then heated while under pressure to cure the polymer precursor into a solid polymeric matrix for the carbon fiber article. Mold tooling is formed of suitable iron-nickel alloys and provided with a hard electroless nickel coating on the mold cavity surface. The iron and nickel alloy provides thermal expansion properties generally matched to those of the articles for the molding of dimensionally accurate parts. The nickel alloy coating provides a durable surface to resist abrasion by the carbon fiber cloth without adversely affecting the expansion properties of the mold, and remains adherent to the base metal during the repeated thermal cycling encountered in high volume production.
摘要:
The quality of painted surfaces of polymeric articles is improved by depositing a coating of a metal such as zinc or zinc alloy on the surface of the article to be painted. For example, zinc is electrodeposited on a conductive surface of the article. The metal coated polymeric surface provides a good base for electrostatic deposition of either liquid or powder paint and the metal surface prevents the formation of defects in the painted surface during heating of the article to dry or cure the paint film.
摘要:
The quality of painted surfaces of polymer composites is improved by first forming an electroless metal coating on the molded surface of the composite and then electroplating a coating of zinc or zinc alloy on the metallized composite surface. The “galvanized” composite surface provides a good base for electrostatic deposition of either liquid or powder paint and the zinc surface prevents the formation of defects in the painted surface during heating of the composite to dry or cure the paint film.