scispace - formally typeset
Search or ask a question
Topic

Spray forming

About: Spray forming is a research topic. Over the lifetime, 1153 publications have been published within this topic receiving 12869 citations. The topic is also known as: spray casting & spray deposition.


Papers
More filters
Patent
02 Oct 1995
TL;DR: In this paper, a system for the recycling of overspray powder during spray forming is provided, which involves providing a refining vessel to contain an electroslag refining layer floating on a layer of molten refined metal.
Abstract: A system for the recycling of overspray powder during spray forming is provided. The system involves providing a refining vessel to contain an electroslag refining layer floating on a layer of molten refined metal. An ingot of unrefined metal is lowered into the vessel into contact with the molten electroslag layer. A current is passed through the slag layer to the ingot to cause surface melting at the interface between the ingot and the electroslag layer. As the ingot is surface melted at its point of contact with the slag, droplets of the unrefined metal are formed and these droplets pass down through the slag and are collected in a body of molten refined metal beneath the slag. The refined metal is held within a cold hearth. At the bottom of the cold hearth, a cold finger orifice permits the withdrawal of refined metal from the cold hearth apparatus. The refined metal passes from the cold finger orifice as a stream. The stream is atomized for spray forming into a preform article on a spray collection station having a solid receiving surface for receiving the atomized metal thereon to form the preform article. The powder produced during the atomization which was not deposited on the solid receiving surface of the spray collection station is recycled onto the top of the molten slag in the electroslag refining station.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used various processing techniques, such as spray forming, thixoforming, and compocasting, to extract reaction products extracted by the electrochemical dissolution.

18 citations

01 Jan 2008
TL;DR: A review of liquid metal jet printing can be found in this article, where the authors discuss the current state of the art in solid free-form fabrication and future applications for this technology.
Abstract: Liquid Metal Jetting (LMJ) is solid freeform fabrication process for producing metal mechanical parts and electronic interconnects. It is a technology similar to ink jet printing where individual molten droplets are accurately printed. LMJ will produce metal parts on demand from a CAD database with functional performance parameters similar to metal parts produced by machining or casting. By controlling solidification rates and metal alloy composition, LMJ is able to produce parts with unique properties such as metal matrices and functionally graded materials. This paper will review the current status of LMJ and future applications for this technology. One emerging manufacturing technology that addresses many challenges in solid freeform fabrication (SFF) is liquid metal jet printing (LMJP). The process is based on technology analogous to ink-jet printing. This agile additive method dispenses individually controlled microballs of molten metals to precise locations. Unlike spray forming and spray deposition process which spray materials in an uncontrolled manner, LMJP dispenses and controls every "single molten droplet" of material to a specific location using digitally stored computer-aided design (CAD) data in a highly reproducible manner. The direct-write, additive nature ofan LMJP system offers an agile approach. Potential applications for LMJP include the ability to rapidly fabricate 3-d mechanical parts and electronic circuitry. This paper discusses research issues in the development ofliquid metal jet printing systems. The technical issues that affect jet operation and the quality ofjetted materials are also discussed. Background of Jetting Research The Frenchman Nollet wrote in 1754 ofobservations made on a low-speed stream issuing from a small diameter nozzle [1]. He commented on the formation of drops, and the ability of a charged rod to deflect them. Lord Raleigh undertook the first thorough and accurate mathematical analysis of liquid jets in the 1870s [2,3]. Rayleigh's theoretical work explained the droplet disintegration mechanism as driven by surface tension induced instabilities. Basset [4] published a theory confirming the role of surface tension induced instabilities and the stabilizing effect of viscosity. Experimentalist A. Haenlein built a system to produce very long (up to 5 meter) water-, glycerinand gasoline-air jets under positive pressures and no external oscillation in 1931 [5]. Weber [6,7], used the data and observations ofHaenlein to generate the first cogent and useful analysis of a viscous cylindrical jet with both symmetric and transverse aerodynamic wave actions although the experimental results did not completely agree with the theory. Electro-mechanical forced stimulation, was studied by Hansell [8] in the 1950's. This greatly broadened the application for jetting. Jet applications changed from fuel injection to rocket propulsion to ink-jet printing. Lee and Spencer [9] used fuel injection mechanisms with fairly broad nozzle length to diameter ratios in the generation of high speed photographic studies ofliquid jets. McCormack et. al. [10] in 1965 described the essential elements ofa modem forced oscillation experimental water jet system employing a vibrating PZT ceramic crystal Jetting for building mechanical structures and parts, which is often called solid freeform fabrication (SFF), started with the use of wax and wax like materials. For example, a patent by Mitchell [11] discloses the generation of an object with liquid wax or similar type material using a jet printer. A later patent of Sanders Prototype shows a desktop jetting machine for generating wax parts. These systems used piezoelectric crystals which limited the systems to low melting point temperature waxes. Considerable research on solidification issues in jetting wax was performed by Gao and Sonin[12]. The jetting of molten metals became the natural next step for mechanical and electronic structures. The field of liquid metal jet printing started in electronics with low temperature solder applications on a suggestion by ffiM in 1972 [13]. Work during the 1980s by Heiber in solder jetting resulted in the first LMJP patent for Philips North American in 1989 [14]. The described drop on demand method utilized a lead zirconium titanate piezo-electric (PZT) crystal to generate

18 citations

Patent
21 Mar 2008
TL;DR: In this article, a material comprising at least one of a metal and a metallic alloy is introduced into a pressure-regulated chamber in a melting assembly, and the material is subjected to a wide-area electron field within the pressureregulated chamber to heat the material to a temperature above the melting temperature to form a molten alloy.
Abstract: Methods and apparatus for producing large diameter superalloy ingots are disclosed. A material comprising at least one of a metal and a metallic alloy is introduced into a pressure-regulated chamber in a melting assembly. The material is subjected to a wide-area electron field within the pressure-regulated chamber to heat the material to a temperature above the melting temperature of the material to form a molten alloy. At least one stream of molten alloy from the pressure-regulated chamber is provided from the melting assembly and is fed into an atomizing assembly, where particles of the molten alloy are generated by impinging electrons on the molten alloy to atomize the molten alloy. At least one of an electrostatic field and an electromagnetic field are produced to influence the particles of the molten alloy. The particles of the molten alloy are deposited onto a collector in a spray forming operation to form an alloy ingot.

18 citations

Journal ArticleDOI
TL;DR: In this paper, contact nanofatigue was performed on a sintered hydroxyapatite and then on amorphous calcium phosphate splats produced on titanium, stainless steel and Co-Cr surfaces, made either at room temperature or on 250°C preheated surfaces.

18 citations


Network Information
Related Topics (5)
Alloy
171.8K papers, 1.7M citations
84% related
Microstructure
148.6K papers, 2.2M citations
83% related
Grain boundary
70.1K papers, 1.5M citations
81% related
Ultimate tensile strength
129.2K papers, 2.1M citations
76% related
Fracture mechanics
58.3K papers, 1.3M citations
76% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202216
202117
202037
201933
201826