Showing papers on "Spray forming published in 2013"

Cold Spray Forming of Inconel 718

Abstract: Inconel 718 was cold spray formed to a 6-mm thickness on an 8-cm diameter aluminum alloy tube using Sulzer Amdry 1718 powder and the Plasma Giken PCS-1000 cold spray system. The effects of spray particle velocity and post-spray heat treatment were studied. Post-spray annealing was performed from 950 to 1250 °C for 1-2 h. The resulting microstructures as well as the corresponding mechanical properties were characterized. As-sprayed coatings exhibited very low ductility. The tensile strength and ductility of the heat-treated coatings were improved to varying levels depending on the heat-treatment and spray conditions. For coatings sprayed at higher particle velocity and heat treated at 1250 °C for 1 h, an elongation of 24% was obtained. SEM micrographs showed a higher fraction of interparticle metallurgical bonds due to some sintering effect. Corresponding fracture surfaces also revealed a higher fraction of dimple features, typically associated with ductile fracture, in the annealed coatings. The results demonstrate that cold spray forming of Inconel 718 is feasible, and with appropriate heat treatment, metallurgical bonding can be increased. The ductility of the spray-formed samples was comparable to that of the bulk material.

Review of gas atomisation and spray forming phenomenology

Abstract: Gas atomisation phenomenology of liquid metals and alloys is both intriguing and instructive. Predating atomistic studies of melt disintegration by almost three decades, it provides a functional means of correlation between drop sizes and processing parameters, as is the case in liquid metal spray forming. In this article a concise but thorough compilation of melt disintegration phenomenology is provided, with emphasis on high pressure gas atomisation, inclusive of notation on mean particle diameters, the role of viscosity, density and other dimensionless ratios that enter as variables in high pressure gas atomization and spray forming, as well as break up of a liquid column and theories of drop disintegration in flight. The article concludes by introducing the very efficient Surface Wave Formation principle which facilitates the treatment of complex atomisation geometries and turbulent regimes.

Microstructure and wear resistance of spray-formed supermartensitic stainless steel

Abstract: Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance1,2. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type) which improve their wear resistances3-9. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (%) and 0.7 wt. (%) processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively). These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS).

Spray forming element for a shower head

Abstract: In a spray forming element for a shower head having a housing, a plurality of axial-flow spray outlet elements, a housing base which has passage openings for the spray outlet elements, each of the spray outlet elements being pivotably mounted in the housing base, and which additionally has a gear mechanism for moving the spray outlet elements, in order to transmit a force to the spray outlet elements, a single gear element having a gate is provided, by means of which the spray outlet elements are positively guided and, during a movement of the gear element, the movement of all the spray outlet elements is carried out simultaneously.

Co-Spray Forming of Gradient Deposits from Two Sprays of Different Tool Steels Using Scanning Gas Atomizers

Abstract: A co-spray forming process was developed to produce gradient deposits from two sprays of different tool steels using scanning gas atomizers. The tool steel melts were atomized and co-sprayed simultaneously onto a horizontally moving flat substrate, resulting in a flat deposit with a gradient zone between two layers of the different steels when the two sprays were overlapped. The gradient deposits were investigated with respect to the porosity, element distributions, microstructure, and hardness. It showed that a sound deposit with a desired gradient zone could be achieved under proper processing conditions.

Microstructure, Tensile Properties and Heat Treatment Process of Spray Formed FGH95 Superalloy

Abstract: The potential of spray forming for microstructural refining can be attractive to the production of superalloys. A f200 mm spray formed FGH95 superalloy round billet that was produced using a single atomizer has considerably homogeneous, small, equiaxed grains. The measured oxygen content is 2×10−5, and the measured porosity is only 0.6%. The achieved yield of deposit is in a good range of about 73. 6%. The microstructure and tensile properties of nickel-based spray formed FGH95 superalloy are analyzed. Also, effects of heat treatment on microstructure were discussed. The results show that the spray formed FGH95 superalloy has higher isotropy in tensile property due to its γ′ phase homogeneous distribution and less defects in the microstructure. Regarding processing procedures, the different heat treatment processes affect the microstructure and γ′ phase homogeneous distribution of spray formed FGH95 superalloy.

Modeling and Simulation of Spray Forming of Clad Deposits with Graded Interface Using Two Scanning Gas Atomizers

Abstract: A three-dimensional shape model based on a surface coordinate tracking method has been developed for clad deposits with graded interface which are spray formed using two scanning gas atomizers. The calculation of element distributions in the deposits has been incorporated into the shape model. On this basis, the deposit shape and the element distributions in the deposit have been simulated. It shows that the scanning mode of the atomizers and the degree of overlapping of the two sprays play important roles in the spray forming of clad deposits. A concentration gradient of chemical elements in the deposits can be achieved under proper processing conditions. Finally, the modeling and simulation of the spray forming of clad deposits have been validated by experimental investigations.

High corrosion resistance spray forming zinc-aluminum alloy and preparation method thereof

Abstract: The present invention provides a high corrosion resistance spray forming zinc-aluminum alloy and a preparation method thereof, belongs to the technical field of material preparation, and relates to a preparation process for a spray forming zinc-aluminum alloy The high corrosion resistance spray forming zinc-aluminum alloy is characterized in that when a spray forming technology is adopted to prepare a Zn-(25-35%)Al-(08-15%)Cu alloy, Cu element can be subjected to complete solid solution in Al and Zn so as to reduce a potential difference between the Zn phase and the Al phase and improve corrosion resistance of the alloy, wherein attached figures in an abstract comprise (a) a polarization curve of an ordinary casting Zn-30Al-1Cu alloy and (b) a polarization curve of a spray forming Zn-30Al-1Cu alloy

Effect of size refinement and distribution of the lubricating lead phases in the spray forming high-leaded tin bronze on wear rates

Abstract: Recently, the wear properties of high-leaded tin bronze were greatly concerned. In this work, the effect of size refinement and distribution of the lubricating lead phases in the spray forming (SF) high-leaded tin bronze on wear rates was studied by using scanning electron microscopy and sliding adhesive wear tests. It was observed that compared to the conventional casting bronze, the SF bronze features finer and more dispersed lead phases that formed more lubricating films in microstructure, which leads to the less wear rates.

Making electrical inductor comprises forming electrical inductor from electrically conductive material by layer-by-layer production process including selective laser melting, spray forming and/or laser wire spraying

Abstract: The method comprises forming an electrical inductor from an electrically conductive material by a layer-by-layer production process. The layer-by-layer production process includes a selective laser melting, a spray forming and/or a laser wire spraying. The method further comprises placing a supporting body on a bottom surface of the inductor, and removing the support body after completion of an inductor geometry. The support body has a support surface having a geometry to be formed corresponds to an effective area at the inductor, and is provided or produced by selective laser melting. The method comprises forming an electrical inductor from an electrically conductive material by a layer-by-layer production process. The layer-by-layer production process includes a selective laser melting, a spray forming and/or a laser wire spraying. The method further comprises placing a supporting body on a bottom surface of the inductor, and removing the support body after completion of an inductor geometry. The support body has a support surface whose geometry to be formed corresponds to an effective area at the inductor, and is provided or produced by selective laser melting, spray forming and/or laser wire spraying process. The electrically conductive material includes a conductive raw material, a powder or a wire, a metallic or non-metallic raw material. The supporting body: is formed from a material having a lower melting point than the electrically conductive material and including a metal, an ice or a wax; includes a soluble material formed of a salt; and is melted or dissolved by the inductor. The inductor geometry is predetermined as a record computer supported by a numerical method. The method is computerized based on a data. A wall thickness of the inductor is varied based on load.

Method for preparing large-size high-vanadium die steel by spray forming process

Abstract: The invention discloses a method for preparing large-size high-vanadium die steel by a spray forming process. By the method, the high-vanadium die steel has fine grain organization by fully using a spray forming and quick solidification process, and macrosegregation is avoided; a large-size high-vanadium die steel blanket is prepared by hot working processes such as subsequent forging; the diameter of the blanket is 250 to 500 mm; the blanket has the characteristics of high intensity, high plasticity, simplicity in forging and rolling and the like; by the method, the problem of difficulty in hot working caused by macrosegregation of the conventional cast large-size high-vanadium die steel is solved; and furthermore, the comprehensive performance of an alloy is improved, and the cost is reduced.

Metal drop spraying device

Abstract: The utility model discloses a metal drop spray device and a method for spraying high-melting metal drops by using the metal drop spray device, so as to solve the technical problem that when the conventional metal drop spray device is used for spraying high-melting light active metal drops, the stability of the spray forming process is poor. The metal drop spray device maintains stable spray of the high-melting metal drops through an automatic spray nozzle dredging device and a spray condition detecting system. The spray nozzle dredging device for spraying high-melting metal and a metal drop spray condition monitoring feedback system are utilized. When the metal drop spray condition monitoring feedback system detects an unstable spray condition and sends out a cleaning signal, an excitation rod is lowered and then instant high positive pressure or negative pressure is introduced into an inner passage of the excitation rod, so that molten metal or air at a spray nozzle is enabled to flow at a high speed to bring out oxide skin or impurities attached to the inner wall of a spray orifice to achieve the purpose of cleaning and dredging the miniature spray nozzle, thus ensuring the stability of the high-melting metal drop spray forming process.

The Heat Treatment Behavior of Super-High Strength Aluminum Alloys by Spray Forming

Abstract: In order to understand the stress corrosion behavior of super-high strength aluminum alloys by spray forming, different aluminum alloys by different heat treatment was made. The results showed that the alloy with peak aging has the most sensitive stress corrosion cracking, the crack can even be seen using eyes; the alloys with two step aging were better than one step aging alloys, the alloys has not been found stress corrosion cracking.

Constitutive Characteristic of Hot Deformation for Spray Formed Superalloy GH738

Abstract: The hot deformation behaviors of spray formed superalloy GH738 were investigated by using of Gleeble-3500 simulator in the temperature range of 950~1200, with a strain rate of 0.13~6.5s-1 and reduction of 50%. The corresponding flow curves were determined and hot deformed microstructures were observed. The results showed that the flow stress decreased with increasing deformation temperature or decreasing strain rate. A full dynamic recrystallization microstructures with fine-equiaxed grains were obtained at the temperature of 1100~1150 and strain rate of 2.6~6.5s-1. The hot deformation activation energy Q was 580.81kJ.mol-1, and the constitutive equation was derived by means of linear regression.

Development of bulk quasicrystalline materials by spray forming

Abstract: In this study, Al-Cu-Fe based stable quasicrystalline alloys were spray deposited in bulk (around 40 kg), with and without addition of Sn. The spray deposited materials were characterized in terms of microstructure, hardness and thermal stability. The results showed that the Al 62.5 Cu 25 Fe 12.5 alloy contains the single quasicrystalline icosahedral phase (i-phase) along with a minor λ-Al 13 Fe 4 phase, whereas the Al 62.5 Cu 25 Fe 12.5 +Sn alloy contains five phas- es: the major i-phase, β-Sn, θ-Al 2 Cu, λ-Al 13 Fe 4 and β-AlFe(Cu) phases. These results have been corroborated by X-ray diffraction (XRD), scanning and transmission electron micros- copy (SEM and TEM) and differential scanning calorimetry (DSC). The hardness value of the Al-Cu-Fe alloy reached 10.5 GPa at 50 g load, while that for Al-Cu-Fe-Sn alloy was some- what lower. DSC analysis showed only one transformation peak at 885.5 o C for i-phase in Al 62.5 Cu 25 Fe 12.5 , indicating the melting temperature. The present study provides an insight into the mechanism of phase and microstructural evolutions during spray forming of the studied alloys. The role of Sn in terms of microstructure and properties is highlighted.

Spreading-Droplet Simulation With Surface Tension Model Using Inter-Particle Force in Particle Method

Abstract: Predicting the spreading behavior of droplets on a wall is important for designing micro/nano devices used for reagent dispensation in micro-electro-mechanical systems, printing processes of ink-jet printers, and condensation of droplets on a wall during spray forming in atomizers. Particle methods are useful for simulating the behavior of many droplets generated by micro/nano devices in practical computational time; the motion of each droplet is simulated using a group of particles, and no particles are assigned in the gas region if interactions between the droplets and gas are weak. Furthermore, liquid-gas interfaces obtained from the particle method remain sharp by using the Lagrangian description.However, conventional surface tension models used in the particle methods are used for predicting the static contact angle at a three-phase interface, not for predicting the dynamic contact angle. The dynamic contact angle defines the shape of a spreading droplet on a wall. We previously developed a surface tension model using inter-particle force in the particle method; the static contact angle of droplets on the wall was verified at various contact angles, and the heights of droplets agreed well with those obtained theoretically. In this study, we applied our surface tension model to the simulation of a spreading droplet on a wall. The simulated dynamic contact angles for some Weber numbers were compared with those measured by Sikalo et al, and they agreed well. Our surface tension model was useful for simulating droplet motion under static and dynamic conditions.Copyright © 2013 by ASME

2A12 aluminum alloy produced by spray forming Conform

Abstract: The spray forming Conform experiment of 2A12 aluminum alloy was accomplished by self-made spray forming Conform equipment.Ultimately,the Al alloy rod with diameter of 7 mm is obtained.The microstructure of the Al alloy rod was analyzed by optical microscopy(OM) and scanning electron microscopy(SEM).The results show that the alloy rod is composed of alternately hat-like coarse-grained layer with grain size under 30 μm and fine-grained layer with grain size under 10 μm.There are a little holes with size less than 3 μm,and the relative density of the product is 99.1%.

Fast solid particle spray forming device

Abstract: The utility model relates to a fast solid particle spray forming device which comprises a fast solid particle generating device and an inductive smelting furnace. The fast solid particle generating device comprises a focusing nozzle and a pipe body. The pipe body comprises a material pipe, a cone-shaped pipe and a sealed gas reversing chamber. A stainless steel gas pipe is axially inserted into the pipe body. The front end of the stainless steel gas pipe is located inside the cone-shaped pipe. High pressure gas introduced from a high pressure gas introducing pipe enters into the stainless steel gas pipe from a ventilating hole on the surface of the stainless steel gas pipe from the gas reversing chamber to form a negative pressure inside the cone-shaped pipe, so the solid particles can be generated in an accelerative manner by solid powder and the solid particles are sprayed from the nozzle. The nozzle is located below the inductive smelting furnace, and is provided with an inner hole penetrating through up and down. The lower end of a molten metal conveying guide pipe at the bottom of the inductive smelting furnace passes through the inner hole of the nozzle. The utility model explores a novel spray forming technology, so that the cooling speed of molten metal drops can be improved to 104.5-106 DEG C/S, and various multiphase and metastable phase composite materials can be produced.

Spray forming equipment and processing control method thereof

Abstract: The invention relates to spray forming equipment and a processing control method thereof. The equipment comprises a feeding device, a high-pressure gas spray device, a workbench, a master control center, a gauge stick, a loop on-off detector and a gauge stick recovery device. When single spray forming is performed, the master control center detects whether melt enters an atomization area to form a loop with the gauge stick or not through the loop on-off detector so as to determine high-pressure gas spray opportunities. When repeated continuous spray forming is performed, the master control center detects whether pressure change of the metal melt reaches a set pressure difference value or not through a pressure sensor so as to control spray opportunities. The spray forming equipment and the processing control method have the advantages that the spray forming equipment can be used for various spray forming processes, the spray opportunities are controlled accurately, and automatic processing is realized.