摘要:
A brazing material comprising a mixture of aluminum brazing powder (i.e. Si, Zn, Cu or Ge), flux, binder, and alcohol for diluting the binder is coated on a surface of an extruded flat tubed strip of aluminum type and this and aluminum type fins are brazed together.
摘要:
A method of metallurgically joining dissimilar metal tubes using a connecting member clad metal tube in which the clad metal is the same or similar metal to a metal of one of the dissimilar tubes to be joined and is susceptible to bonding by welding. The underlying clad metal connecting member metal is a dissimilar metal which is susceptible to bonding by soldering.
摘要:
A method of avoiding generation of waste water while brazing components made of aluminium or an aluminium alloy using a flux, especially a flux composed of an aqueous suspension of potassium fluoroaluminate. Since used suspension is replaced with fresh suspension after a given period of time and the apparatus regularly have to be cleaned, waste water is produced which contains flux, e.g. potassium fluoroaluminate. In the past, such waste water has been discharged into the environment. It has now been discovered that such waste water can be recycled to the brazing process after separation of the flux. In this manner, the production of waste water can be largely avoided. Since surfactants are frequently used, and these are likewise recirculated, a corresponding saving in terms of surfactant is possible. Furthermore, the environment is protected correspondingly.
摘要:
A method and apparatus for micromachining and microdrilling which results in a machined part of superior surface quality is provided. The system uses a near diffraction limited, high repetition rate, short pulse length, visible wavelength laser. The laser is combined with a high speed precision tilting mirror and suitable beam shaping optics, thus allowing a large amount of energy to be accurately positioned and scanned on the workpiece. As a result of this system, complicated, high resolution machining patterns can be achieved. A cover plate may be temporarily attached to the workpiece. Then as the workpiece material is vaporized during the machining process, the vapors condense on the cover plate rather than the surface of the workpiece. In order to eliminate cutting rate variations as the cutting direction is varied, a randomly polarized laser beam is utilized. A rotating half-wave plate is used to achieve the random polarization. In order to correctly locate the focus at the desired location within the workpiece, the position of the focus is first determined by monitoring the speckle size while varying the distance between the workpiece and the focussing optics. When the speckle size reaches a maximum, the focus is located at the first surface of the workpiece. After the location of the focus has been determined, it is repositioned to the desired location within the workpiece, thus optimizing the quality of the machined area.
摘要:
A process and apparatus for projection welding of overlapping nonferrous sheets, particularly thin aluminum sheets. One of the sheets is provided with a projection therein, and the sheets are positioned so that the tip of the projection contacts a surface of the other sheet. The sheets are not subjected to surface pretreatment to remove the surface oxides therefrom. A projection welding head assembly is positioned with the electrode thereof engaged with one of the sheets, and the other sheet is positioned against a stationary backup or electrode. The electrode of the welding head imposes, in rapid time succession, a series of welding pulses to the overlapping contacting sheets. The series of welding pulses includes two and preferably three pulses which progressively step up in amperage to provide for precise control of the heating of the projection and the associated contact area on the other sheet to cause heating to the plastic state, and then forging (i.e. collapsing) of the projection with subsequent and progressive creation of the desired weld nugget. The series of weld pulses also preferably includes, at the end of the series, one or two pulses which progressively step down in current magnitude to permit greater control over the plasticity of the projection and the forging together of the overlapping sheets to create the desired weld bead.
摘要:
The present invention is a brazing composition for brazing a tube made of aluminum or aluminum alloy and a fin made of aluminum or aluminum alloy when manufacturing a heat exchanger such as evaporators, condensers, radiators, etc., comprising a powder of Al--Si--Zn alloy and binder, wherein the content of Zn in the powder of Al--Si--Zn alloy is in a range of 10 to 55 wt %.
摘要:
In a brazing method, a flux-mixed liquid is prepared by mixing a brazing flux with a quick-drying oil. The flux-mixed liquid, when it is spread to an aluminum or aluminum alloy work, fixes the brazing flux to the work by a quick-drying character of the quick-drying oil within a short time. Also, in the brazing method, the flux-mixed liquid is prepared by mixing the brazing flux with an aqueous solution in which a solid lubricant is melted in water. The solid lubricant melts in water at or above a prescribed temperature, and forms a film when the temperature is below the prescribed temperature. The flux-mixed liquid, when it is spread to the work, immediately forms the film due to a drop in temperature below the prescribed temperature and fixes the brazing flux to the work by the film within a short time.
摘要:
The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in targets (40) having metallic layers (64,68) and a dielectric layer (66). The invention employs a first laser output of high power density to ablate the metallic layer and a second laser output of a lower power density to ablate the dielectric layer. The parameters of the output pulses (62) are selected to facilitate substantially clean, sequential drilling or via formation. These parameters typically include at least two of the following criteria: power density first above and then below the ablation threshold of the conductor, wavelength less than 400 nm, a temporal pulse width shorter than about 100 nanoseconds, and a repetition rate of greater than about one kilohertz. The ability to generate ultraviolet light output pulses at two power densities facilitates the formation of depthwise self-limiting blind vias in multilayer targets, such as a target composed of a layer dielectric material covered on either surface by a layer of metal.
摘要:
The invention relates to a method of manufacturing a replication master tooling article suitable for manufacturing replicated articles by machining a substrate surface with laser energy to produce a plurality of geometric structures in the substrate, the geometric structures having side surfaces extending from the surface of the substrate into the substrate.
摘要:
The present invention is directed to a unique composite trailer and van type container for the transport and management of bulk freight utilizing steel and aluminum components to take advantage of the durability and light weight of aluminum components and the proven strength and fabrication ease of structural steel. More particularly, the composite trailer and container comprises the integration of two dissimilar metals secured together by using a bi-metal intermediate element. The bi-metal intermediate element provides for the welding of different metals together thereby forming a superior bond between the intermediate element and dissimilar metals. This construction also makes it possible to eliminate the galvanic corrosion so often experienced with contact between different metals.