摘要:
Al—Mnx/Al—Mny multilayers with a wide range of structures ranging from microcrystalline to nanocrystalline and amorphous were electrodeposited using a single bath method under galvanostatic control from room temperature ionic liquid. By varying the Mn composition by −1-3 at. % between layers, the grain sizes in one material can be systematically modulated between two values. For example, one specimen alternates between grain sizes of about 21 and 52 nm, in an alloy of average composition of 10.3 at. % Mn. Nanoindentation testing revealed multilayers with finer grains and higher Mn content exhibited better resistance to plastic deformation. Other alloy systems also are expected to be electrodeposited under similar circumstances.
摘要:
Al—Mnx/Al—Mny multilayers with a wide range of structures ranging from microcrystalline to nanocrystalline and amorphous were electrodeposited using a single bath method under galvanostatic control from room temperature ionic liquid. By varying the Mn composition by −1-3 at. % between layers, the grain sizes in one material can be systematically modulated between two values. For example, one specimen alternates between grain sizes of about 21 and 52 nm, in an alloy of average composition of 10.3 at. % Mn. Nanoindentation testing revealed multilayers with finer grains and higher Mn content exhibited better resistance to plastic deformation. Other alloy systems also are expected to be electrodeposited under similar circumstances.
摘要:
Provided in one embodiment is a method, comprising: sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy, wherein at least some of the nanocrystalline particulates may include a non-equilibrium phase comprising a first metal material and a second metal material, and the first metal material may be soluble in the second metal material. The sintered nanocrystalline alloy may comprise a bulk nanocrystalline alloy.
摘要:
Coated articles and methods for applying coatings are described. The article may include a base material and a coating comprising silver formed thereon. In some embodiments, the coating comprises a silver-based alloy, such as a silver-tungsten alloy. The coating may, in some instances, include at least two layers. For example, the coating may include a first layer comprising a silver-based alloy and a second layer comprising a precious metal. The coating can exhibit desirable properties and characteristics such as durability (e.g., wear), hardness, corrosion resistance, and high conductivity, which may be beneficial, for example, in electrical and/or electronic applications. In some cases, the coating may be applied using an electrodeposition process.
摘要:
A method for protecting a threaded metal joint from galling and corrosion includes providing a nanocrystalline coating on the metal surface. The nanocrystalline coating can include a solid or liquid lubricant to protect against wear. Threaded metal joint surfaces coated with the nanocrystalline coating can resist galling under high pressure and high torque, even after several fastening and unfastening operations and also over a long period of time. Protection from corrosion is also provided by the nanocrystalline coating. The method and nanocrystalline coating provide metal surfaces with both lubrication and protection against corrosion. Problems such as removal or leakage, which are associated with protective compounds that use oils, are avoided. The nanocrystalline coatings may be layers of the same material, or layers of differing materials, such as layers with lubricating particles dispersed throughout, and layers without lubricating particles. Such coatings may provide reduced wear, friction, corrosion and galling. Such coated threaded articles are very useful in messy and dirty environments, such as oil production and oil handling industries.
摘要:
Methods for the use of nanocrystalline or amorphous metals or alloys as coatings with industrial processes are provided. Three, specific, such methods have been detailed. One of the preferred embodiments provides a method for the high volume electrodeposition of many components with a nanocrystalline or amorphous metal or alloy, and the components produced thereby. Another preferred embodiment provides a method for application of a nanocrystalline or amorphous coatings in a continuous electrodeposition process and the product produced thereby. Another of the preferred embodiments of the present invention provides a method for reworking and/or rebuilding components and the components produced thereby.
摘要:
Bipolar current electrodeposits a nanocrystalline grain size. Polarity Ratio relates the absolute value of time integrated amplitude of negative polarity and positive polarity current. Grain size can be controlled in alloys of two or more components, one of which being a metal, and one of which being most electro-active. Typically the more electro-active material is preferentially lessened in the deposit during negative current. The deposit is relatively crack and void free. Grain size is typically a function of deposit composition, which is typically a function of Polarity Ratio. Specified grain size can be achieved by selecting a corresponding Polarity Ratio. Coatings can be in layers, each having a grain size, which can vary layer to layer and also in a graded fashion. A finished article may be built upon a substrate of electro-conductive plastic, or metal, including steels, aluminum, brass. The substrate may remain, or be removed.
摘要:
Coated articles and methods for applying coatings are described. The article may include a base material and a coating comprising silver formed thereon. In some embodiments, the coating comprises a silver-based alloy, such as a silver-tungsten alloy. The coating may, in some instances, include at least two layers. For example, the coating may include a first layer comprising a silver-based alloy and a second layer comprising a precious metal. The coating can exhibit desirable properties and characteristics such as durability (e.g., wear), hardness, corrosion resistance, and high conductivity, which may be beneficial, for example, in electrical and/or electronic applications. In some cases, the coating may be applied using an electrodeposition process.
摘要:
A mechanical structure is provided with a crystalline superelastic alloy that is characterized by an average grain size and that exhibits a martensitic phase transformation resulting from a mechanical stress input greater than a characteristic first critical stress. A configuration of the superelastic alloy is provided with a geometric structural feature of the alloy that has an extent that is no greater than about 200 micrometers and that is no larger than the average grain size of the alloy. This geometric feature undergoes the martensitic transformation without intergranular fracture of the geometric feature.
摘要:
Methods to enhance the quality of grain boundary networks are described. The process can result in the production of a metal including a relatively large fraction of special grain boundaries (e.g., a fraction of special grain boundaries of at least about 55%).