Showing papers on "Spray forming published in 2012"

Microstructure evolution and mechanical properties of T15 high speed steel prepared by twin-atomiser spray forming and thermo-mechanical processing

Abstract: Spray formed T15 high speed steel (HSS) billets were deposited using a state-of-the-art twin-atomiser spray forming facility. The effects of post thermo-mechanical processing (hot isostatic pressing and hot forging) and heat treatment on the microstructure and mechanical properties were investigated. As-deposited billet has a density over 99.3% of the theoretical value and no measurable macro-segregation was observed. The microstructure consists of the equiaxed grains with mean size of ∼18 μm and MC- and M 6 C-type carbides non-uniformly distributed inside the grains and along the grain boundaries. After optimal thermo-mechanical processing and heat treatment, the microstructure was composed of equiaxed fine tempered martensites, and refined M 6 C and MC spherical carbides particles uniformly distributed along the grain boundaries and inside the grains. The hardness reached HRC68 after thermo-mechanical processing, and the corresponding impact toughness and bending strength reached 27 J/cm 2 and 4600 MPa respectively. Although HIP cannot increase the bending strength significantly, it can effectively improve the impact toughness through refining and globurizing carbides.

Gas Atomization of Aluminium Melts: Comparison of Analytical Models

Abstract: A number of analytical models predicting the size distribution of particles during atomization of Al-based alloys by N2, He and Ar gases were compared. Simulations of liquid break up in a close coupled atomizer revealed that the finer particles are located near the center of the spray cone. Increasing gas injection pressures led to an overall reduction of particle diameters and caused a migration of the larger powder particles towards the outer boundary of the flow. At sufficiently high gas pressures the spray became monodisperse. The models also indicated that there is a minimum achievable mean diameter for any melt/gas system.

Chemistry and tensile properties of a recycled AA7050 via spray forming and ECAP/E

Abstract: The aim of this work is to evaluate the conjugation of advanced processing techniques, such as spray forming, extrusion and ECAP as a processing route for reuse of machining chips generated during aircrafts manufacturing parts from AA7050-T7451 raw material plates supplied according to AMS 4050H1. In this way, the sprayforming process was used for remelting, and billet production, followed by extrusion and ECAP. At the end of the process, an artificial aging according to AMS 2772E 2 was conducted. An assessment of chemical composition, microstructure, and mechanical properties evolution throughout the process were performed. The results have showed that this proposed route may be used as a potential technological route for secondary aluminum source. For extrusion route for overaged condition, 144 MPa yield strength and 14% of elongation was attained. Beside this, at this stage of work, was verified that the hot extrusion process is more effective for reduction of porosity and microstructure development than ECAP, but on the other hand this one has reduced porosity dispersion significantly for the extrusion parameters adopted. The adopted homogenization schedule, followed by artificial aging after has resulted in excessive grain growth.

Aluminum alloy material with ultrahigh strength, high toughness and wear resistance and preparation method thereof

Abstract: The invention relates to an aluminum alloy material with ultrahigh strength, high toughness and wear resistance. The aluminum alloy material comprises the following components in percentage by weight: 7-10wt% of Zn, 1.3-1.8wt% of Mg, 1.7-2.0wt% of Cu, 0.1-0.2wt% of Zr, 0.1-0.2wt% of Ni, 2.0-2.7wt% of Si and the balance of Al. The aluminum alloy material with ultrahigh strength, high toughness and wear resistance in the invention further comprises rare-earth elements, such as one or more of Y, Nd, Sr, Gd and Ce, with the additive amount of 0.01-0.05% by weight. The aluminum alloy material disclosed by the invention is prepared through spray forming, thermal-deformation processing and thermal treatment. The alloy material has ultrahigh strength, high toughness and high wear resistance and has the advantages of overcoming the technical defect that alloy is easy to wear in the prior art, and prolonging the service of equipment, thus, the alloy material can be utilized to a larger extent, and the production cost is reduced.

Spray forming system for preparing alloy and metal-based composite parts

Abstract: The invention relates to a spray forming system for preparing alloy and metal-based composite parts. The spray forming system is characterized in that: an intermediate frequency induction melting furnace, a transfer crucible, a high-pressure gas nozzle, a receiver, a three-dimensional workbench and an ultrasonic transducer tool head are arranged in a vacuum tank; the vacuum tank is connected witha vacuum machine through a pipeline, the side wall of the vacuum tank is provided with a feeding hole and a discharge hole, and the intermediate frequency induction melting furnace is fixed on a supporting plate through a melting furnace bracket and connected with a servo motor mechanism for controlling the movement of the intermediate frequency induction melting furnace; and the transfer crucible is arranged at the lower part of one side of the intermediate frequency induction melting furnace and connected with a diversion pipe through a threaded through hole in the bottom of the transfer crucible, and the ultrasonic transducer tool head is fixed on the fixed bracket. The spray forming system can effectively thin atomized granules and improve the metal yield, and is advanced and reliablein technical routes, low in production cost and easily controlled in product quality.

Effect of Cold Rolling on the Mechanical Properties of Spray Cast Al-6Si-20Pb Alloy

Abstract: Porosity, hardness and microstructural studies of cold rolled spray cast Al-6Si-20Pb alloy for different percentage of thickness reduction were conducted from top to bottom and from centre to periphery of the deposit. Porosity was found to decrease and hardness was found to increase with the increase in percentage of thickness reduction. Aluminum grains were observed to become coarser with the increase in percentage of thickness reduction.

Rapid Solidification of an Al-5Ni Alloy Processed by Spray Forming

Abstract: Recently, intermetallic compounds have attracted much attention due to their potential technological applications as high-temperature materials. In particular the intermetallic compounds, associated with the Al-Ni binary system stand out as promising candidates for high-temperature materials for the use in harsh environments. It is expected that a bulk Al-Ni alloy may exceed the strength of many commercial materials. The great challenge in developing these alloys is to manipulate the solidification thermal parameters in order to obtain the desired microstructural features. One of the indicated routes to obtain very refined intermetallic phases dispersed in the microstructure is the spray forming process. The dendritic and eutectic growth dependences on cooling rate are already known for directionally solidified (DS) hypoeutectic Al-Ni alloys. In the case of rapidly solidified (RS) samples, extrapolations of such experimental laws are needed, which can be very helpful to estimate realistic values of high cooling rates imposed during the spray forming process. The present study aims to compare directionally solidified and spray-formed Al-5wt. (%)Ni alloy samples with a view to providing a basis for understanding how to control solidification parameters and the as-cast microstructure. The Al-5.0wt. (%)Ni alloy was shown to have a cellular morphology for the overspray powder size range examined (up to 500 µm). The mean cell spacing decreased from 5.0 to 1.1 µm with the decrease in the powder average diameter. It was found that the experimental cooling rates imposed during the atomization step of the overspray powder solidification varied from 103 to 2.104 K/s. The DSC trace depicted a crystallization peak of an amorphous structure fraction in the smallest Al-5.0wt. (%)Ni alloy powder size range (<32 µm) estimating a 15 µm critical diameter of amorphous powder in the binary Al97.5Ni2.5 (at%) alloy.

Cooling conditions for the generation of bulk metallic glasses by droplet deposition

Abstract: The cooling rate during material processing until glass transition rate is the key parameter for the production of bulk metallic glasses. But in the past, little attention has been paid to advanced production techniques such as deposition of molten metal sprays or spray forming, which offer elevated cooling rates. In this work, cooling conditions during spray forming were investigated due to its utmost importance for producing amorphous structures. Spray forming is treated in this work as a three step cooling process consisting of droplet flight phase, splat phase and deposit phase. All cooling steps were simulated for different droplet sizes. The surface temperature of the deposit was found to play an important role in the production of metallic glasses via spray forming. The simulation model can be used to find suitable spray conditions for the generation of bulk metallic glasses.

Thickness uniformity and microstructure of disc shape spray formed Al-Si-Pb alloys

Abstract: Spray forming technique was employed to produce a near net-shape disc of Al-Si-Pb alloys. Different substrate distances and inclination angles were studied to obtain the disc shape preforms. The substrate was also offset by 40 mm from the atomizer axis in case of 15 and 30 degree inclination angles. Microstructures were investigated in different regions of the preforms. Results exhibited equiaxed grains of primary Al and Si was present within these grains and along the grain boundary. The size of the Al grains was 20-30 µm and size of Si particles was sub-micron to 5 µm. The size of Pb particles varied from sub-micron to 20 µm and it was uniformly dispersed throughout the aluminum phase. Copyright © 2011 VBRI press.

Porosity in Disk Shape Spray Formed Al-Si-Pb Alloy Preform

Abstract: Spray forming technique was employed to produce a disc shape preform of Al-Si-Pb alloys. Porosity of this disc was investigated as a function of lead content and the distance from centre to periphery of the disc. The porosity decreases with distance from centre to periphery for all compositions of lead. The decay rate in porosity increases with the increase in lead content. Also the decay rate in porosity decreases towards the periphery of the deposit. The areas having large and small amount of porosity were observed in the microstructure of Al-Si-Pb alloys. The large and small amount porosity areas belong to the lead and aluminum rich areas, respectively.

Spray forming atomization device for applying static electricity to metal liquid and atomization method for device

Abstract: The invention relates to a spray forming atomization device for applying static electricity to metal liquid and an atomization method for the device. The device mainly comprises a high-voltage direct-current power supply, an electrode rod, a crucible, a melting and holding furnace, a graphite plug, an atomizer, a metal depositor, an insulation pad, an electric brush and the like. An electrostatic atomization technology is introduced into a spray forming process, a negative electrode of the high-voltage direct-current power supply is connected with a metal solution, a positive electrode of the high-voltage direct-current power supply is connected with the metal depositor, the graphite plug is lifted for spray after metal is directly melted in the melting furnace, and metal jet is subjected to induction charging, so that atomization power is increased into air flow drag force and electrostatic repulsion; meanwhile, the surface tension of the metal liquid can be changed due to the newly added electrostatic action, atomization quality can be improved by applying the static electricity comprehensively, and a new spray forming atomization technology for improving the atomization quality by changing the property of the metal liquid for the first time is provided.

Metal Matrix Composites: Magnesium

Abstract: In this article, special attention is drawn to magnesium-based metal matrix composites (MMCs). The first part reviews the conventional and the newer processing techniques appropriate for the fabrication of magnesium matrix composites. These routes are divided into liquid- and solid-state fabrication, in situ, and spray forming methods. After introducing the matrix and its properties, reinforcements are described (continuous and discontinuous) and the obtained composites are discussed. The interface is also described. Finally, recent applications, such as medical purpose, are reported. Keywords: metal matrix composite; nanocomposite; magnesium; mechanical properties; processing techniques

Spray Forming of al Alloys: experiment and theory

Abstract: Close coupled gas atomization has been studied. Pitot tube gas flow measurements support a postulate of transition from an initial sonic to a supersonic and a final sonic state along the convergence region of the jets. Predictions of the d50 median diameter utilizing a two phase model for primary and secondary break up correlate strongly with experimental results from He-atomized Al alloys by a factor of 0.8216.

Dry sliding wear behaviour of spray formed ZrSio 4 reinforced Al-Si-Sn alloy

Abstract: The wear behaviour of Al-12Si alloy and Al-12Si-Sn/ZrSiO4 composite prepared by spray forming technique has been investigated under dry sliding conditions at different loads and temperatures. The wear rate of spray formed composite was significantly lower than that of as cast Al-12Si alloy. Paricle size of ZrSiO4 was varied from 53 to 105 µm and the amount of Sn was taken 5 and 10 %. Smaller particles of ZrSiO4 were able to reduce the wear rate up to more extent as compared to that of bigger particles in the same matrix. On increasing the amount of Sn the wear rate decreases. Copyright © 2011 VBRI press.

Study of Ageing Treatment on Spray Forming Al-Zn-Mg-Cu Alloy

Abstract: The Al-Zn-Mg-Cu (7A04) alloys were prepared by using the method of spraying forming and the hot extrusion. The changes of microstructure and mechanical properties of the spray deposited Al-Zn-Mg-Cu alloy underwent ageing, regression and reageing treatment (RRA) was studied by scanning electron microscopy, X-ray diffraction and other methods. The results show that the tensile strength of the alloy aged at 120°C for 24 hours can reach the peak value (760MPa), but the elongation is only 4.8 percent. The toughness of the alloy regression treated at 160°C for 2 hours can increase to 9.0 percent, but its tensile strength decreases greatly (680MPa). The reaging treatment at 120°C can make the tensile strength up to 740MPa, while the elongation which is 8.2 percent still keeps a higher level.

Friction stir welding weld set for spray forming of Al (aluminum)-Zn (zinc)-Mg (magnesium)-Cu (copper) aluminum alloy

Abstract: The invention discloses a friction stir welding weld set for spray forming of Al (aluminum)-Zn (zinc)-Mg (magnesium)-Cu (copper) aluminum alloy, which is of a combined structure including a clamping body, a pin tool and a fastening screw, wherein the pin tool is mounted at one end of the clamping body, the clamping body is a large-and-small-diameter cylinder, the end face of a large-diameter cylinder is provided with a central blind hole, the outer circumferential face of the large-diameter cylinder is provided with a threaded through hole which is used for mounting the fastening screw and perpendicular to the central line of the central blind hole, the pin tool is a 'T'-shaped cylinder, a conical tool pin is arranged on the upper plane of the 'T'-shaped cylinder, and a lower cylinder of the 'T'-shaped cylinder is mounted in the central hole mounted on the end face of the large-diameter cylinder of the clamping body The friction stir welding weld set has the advantages that expensive high-melting-point heat-resistant high-strength materials for manufacturing the pin tool are saved, machining and manufacturing cost is reduced, dimension modification of the pin tool is facilitated, and practicality of the weld set is enhanced

Device for improving atomization quality by outflow of annular liquid metal

Abstract: The invention relates to a device for improving atomization quality by outflow of annular liquid metal. The device comprises a smelting furnace, a crucible, a flow guiding pipe, an outflow opening, a central core, a positioning disc, a graphite plug and an atomizer. Particularly, in a spray forming process, the outflow form of the liquid metal is changed by changing the structure of the outflow opening of the crucible, so that liquid metal flow is contacted with atomized gas for atomization in a hollow jet flow mode; therefore, atomization pressure is not required to be improved, and the aim of improving the atomization quality on the premise of higher mass flow rates is fulfilled. Simultaneously, the annular liquid metal has larger area in the spraying process, so that development tendency requirements on production of large-sized deposition blanks can be met, and a spray forming technology is promoted to be applied in the actual production process.

Simulations of Temperatures, Residual Stresses, and Porosity Measurements in Spray Formed Super Alloys Tubes

Abstract: Spray Forming is a technology to produce near net shape components and preforms. A simulation tool for the temperature distribution which incorporates all necessary sub steps (metal deposition on the substrate, heat transfer across the surface by convection and radiation) is developed to calculate residual stresses during the different process steps. The resulting temperature distribution was used to calculate the stresses during all process stages. Thermal histories of temperatures at certain positions will be shown. The dependency of the residual stress on the thermal history of the material was examined. Mainly at the interface substrate/deposit, a region with elevated porosity was observed. Porosity measurements will be presented. Introduction Spray forming combines two distinct processes. In the first step, liquid metal is atomized into a spray cone of droplets. The impinging droplets form a near net shape product on a substrate in the second step. In contrast to spray formed billets, (in which the surface temperature is mostly constant) the substrate surface temperature just ahead of the spray cone is a strong function of time. Therefore, the obtained material density or the porosity is a function of the surface temperature. Porosity measurements of super alloy rings were reported in [1]. The results show that at temperatures above 1100°C, low porosity is measured. High convection coefficients in the vicinity of the spray cone cause a temperature increase for initially cold substrates and a temperature drop for initially hot substrates. Mathematical models for the temperature distributions in the spray formed tubes were created [2, 3, 4, 5, 6]. A detailed analysis of heat exchange phenomena on small time scales is given by [3]. The temperature distribution in substrate and deposit act as a load for the developing residual stresses. Due to the difficulties in simulating stresses in spray formed deposits, only a few papers have been presented [7, 8, 9]. Mechanical properties for IN718 are reported for temperatures up to 1100°C [10]. The uncertainties in the mechanical properties cover a small temperature range, from 150K to the solidus temperature of the material. The resulting stresses are mainly affected by thermal strains. Specifically, they depend on the heating and cooling rates during the spray process, and later on post spray conditions. Therefore, the knowledge of the temperature distribution during the spray forming process, as well as the behavior of temperature during heat treatment and cooling processes is of great importance in the understanding of the development of residual stresses.

Device for manufacturing alloy-metal-based parts by spray forming

Abstract: The utility model relates to a device for manufacturing alloy-metal-based parts by spray forming. The device is characterized in that an intermediate frequency induction melting furnace, a transfer crucible, a high-pressure gas nozzle, a receiver, a three-dimensional workbench and an ultrasonic transducer tool head are arranged in a vacuum tank; a vacuum tank body is connected with a vacuum machine by a pipeline, a material feeding and discharging port is arranged on the side wall of the vacuum tank body, the intermediate frequency induction melting furnace is fixed on a support plate by a melting furnace bracket and is connected with a servo motor mechanism for controlling the movement of the intermediate frequency induction melting furnace; and the transfer crucible is arranged below one side of the intermediate frequency induction melting furnace and connected with a flow guide tube by a thread through hole in the bottom of the transfer crucible, and the ultrasonic transducer tool head is fixed on a fixing bracket. According to the device, particles can be refined and atomized effectively, the metal yield is improved, the technology course is advanced and reliable, the production cost is low, and the product quality is easy to control.

Progress of Research on P/M and Spray-Formed Superalloy in ISCPM, USTB

Abstract: For meeting the demands of P/M disks, ISCPM began to research work on P/M superalloys at the beginning of 21st century. The study mainly can be divided into three parts: 1. Systematic engineering research on improving argon atomization process, including refractory improvement and technological parameters optimization, and powder metallurgy route; 2. Research on spark plasma discharge (SPD) process, which is an innovative technology for making ultra-fine and clean superalloy powder; 3. Research on spray forming. We use spray-forming technology to make the FGH4095 disk alloy. The nitrogen spray-formed superalloy after HIP, isothermal forging and heat treatment, shows encouraging properties, which shows the potential for making high performance superalloy disks. Introduction Research on P/M superalloys in China has made significant progress especially in recent years [1-9]. China-made P/M disks are being considered for application in a few types of airplane engines. But until now the majority of the P/M turbine disks were imported from Russia, which are afforded as components of imported high pressure gas turbines. With the purpose of reducing the dependence on imported P/M turbine disks in China, at the beginning of 21st century, our group began to research work on P/M superalloys [10, . On the basis of understanding from long–term research on P/M and spray-formed high speed steels with nitrogen atomization, hot extrusion, isothermal forging and HIP, and in the absence of funding from national projects on P/M superalloy, ISCPM established cooperation with large national companies – Fu Shun Special Steel Shares Co., Ltd and Guizhou Anda Aviation Forging Co., Ltd and the group of Professor Udo Fritsching and Dr. Volker Uhlenwinkel, IWT University Bremen. With the help of these companies and research groups, ISCPM is making progress on P/M and spray-formed superalloys in following aspects. The superalloy chosen for this research is a first generation P/M superalloy with high strength FGH4095, which is equivalent to René95. The designed chemical composition of FGH4095 is shown in Table 1. Table 1. The designed chemical compositions of FGH4095 Element Ti Al Cr Co W Mo Content (wt.%) 2.3~ 2.7 3.3~ 3.7 12.0~ 14.0 7.0~ 9.0 3.3~ 3.7 3.3~ 3.7 Element Nb Zr B C Ni Content (wt.%) 3.3~ 3.7 0.03~ 0.07 0.006~ 0.015 0.04~ 0.09 Bal. Improved argon atomization process and powder metallurgy route We have improved argon atomization for the production of clean powder with high yield of fine powder (-270 mesh) and low oxygen content. To guarantee the quality of the final product, an experimental atomization facility with capacity of melting 10Kg of material, and which enables powder handling to be undertaken in vacuum (including sieving and classification, removing ceramic inclusions, sealing and welding capsules for HIP etc.) was self-designed and installed. The systematic engineering research has also included the improvement of refractories. We selected Al2O3, MgO, BN for making liners and delivery tubes, and studied the effect of ZrO2 foam filter for removing ceramic inclusions. After the argon atomization process, the superalloy powders have been produced with oxygen content of <100ppm and 35wt% yield of particles that show a diameter <53μm (-270 mesh). After being sealed in stainless steel capsule, degassed and hot-isostatic pressed, specimens were heat treated with two schedules: A:1140°C×1h, furnace cooling/ 870°C×1h, furnace cooling/ 650 ×24h, air cooling. °C B:1140°C×1h, furnace cooling/ 1060 ×4h, °C furnace cooling/ 870 ×1h, °C furnace cooling/ 650 ×24h, air cooling. °C After the heat treatment, the mechanical properties at room temperature and at 650°C of the prepared P/M FGH4095 superalloy are shown in Figure 1. The column graphs in Figure 1 shows that higher strength and better ductility at 650°C, are obtained with the B schedule. This might be attributed to the growth of primary γ’ and reduction of Ti, Al in surrounding substrate due to the intermediate holding at 1060 °C for 4 hours with furnace cooling.

Microstructural Feature and Aging Characteristics of Spray-Formed Cu-5Ni-10Sn Alloy

Abstract: In this study, Cu-5Ni-10Sn(wt%) spinodal alloy was manufactured by gas atomization spray forming, and the microstructural features and mechanical properties of Cu-5Ni-10Sn alloy have been investigated during homogenization, cold working and age-hardening. The spray formed Cu-5Ni-10Sn alloy consisted of an equiaxed microstructure with a mixture of solid solution -(CuNiSn) grains and lamellar-structure grains. Homogenization at and subsequent rapid quenching formed a uniform solid solution -(CuNiSn) phase. Direct aging at from the homogenized Cu-5Ni-10Sn alloy promoted the precipitation of finely distributed ` or phase throughout the matrix, resulting in a significant increase in microhardness and tensile strength. Cold working prior to aging was effective in strengthening Cu-5Ni-10Sn alloy, which gave rise to a maximum tensile strength of 1165 MPa. Subsequent aging treatment slightly reduced the tensile strength to 1000-1100 MPa due to annealing effects.

Overspray Powder Characterization of Fe-Based Glassy Alloy

Abstract: Powder of Fe72Nb4Si10B14 (%at) glassy alloy was obtained by gas atomization in order to investigate the possibilities of amorphous phase formation due to the high cooling rates (103 105 K/s) involved in this process. The ratio between the gas volumetric and the metal mass flow rates used was 1.0, and nitrogen (N2) was used as the atomization gas. The powder, sieved in different granulometric size ranges, was characterized through: X-ray diffratometry (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Fe72Nb4Si10B14 (%at) bulk metallic glass (BMG) showed completely or partially glassy structure depending on the size range. The obtaining of powders with glassy structure that could be applied as shot penning powder particles and thermal spray feeding powder for metallic coatings or would make possible the production of bulk glassy materials by warm consolidation of such powders or even a millimeters thick deposit obtained by spray forming with glassy or metastable microstructure that would be very interesting considering applications as soft ferromagnetic parts.

EFFECT OF Nb ON THE MICROSTRUCTURE AND PROPERTIES OF SPRAY FORMED M3 HIGH SPEED STEEL

Abstract: Spray forming with a short process chains has been proven to be a powerful tool for the production of high-alloyed materials.Niobium,as a strong former for the carbide,will mainly form primary MC carbides,such as NbC,which can be formed via the reaction between Nb and C atoms at the beginning of solidification,and it can act as the inoculants and refine the cast structure of steel which can mainly form primary MC carbides.M3 high speed steel with or without Nb addition were prepared via spray forming.The effect of Nb on the microstructure of spray formed M3 high speed steel was investigated by SEM,EDX and XRD methods;the friction performances of these two steels were studied by SRV high temperature tribometer and 3D white-light interfering profilometer.The results show that the amount of primary MC carbides can increase sharply while the reduction of the amount of primary M_2C due to the substitution of 2%Nb for 1%V(mass fraction) in M3 high speed steel.For the high cooling rate during the spray forming,the primary MC carbides can be refined and dispersed.Large number of primary MC carbides can improve the abrasive wear resistance of M3 high speed steel,but cannot enhance its oxidation resistance;M3 high speed steels containing Nb possess high tempering resistance.

Material increase manufacturing method through multi-metal liquid spray deposition

Abstract: The present invention relates to a material increase manufacturing technology in the mechanical manufacturing field. Disclosed is a material increase manufacturing method through multi-metal liquid spray deposition. The material increase manufacturing method through metal liquid spray deposition comprises: establishing a computer three-dimensional physical model for parts, and performing z-direction layering of the established model, to obtain a scan path of a current layer; melting various types of metal materials to be deposited into liquids by using heating devices, respectively; selecting, according to information of the current layer, nozzles to perform spray forming of the liquid metal materials along the scan path of the current layer; and moving by a layer height after the spraying of one layer is completed. The present invention adopts a multi-nozzle, multi-metal spray deposition rapid forming method, and metal parts processed by using this material increase manufacturing method has good internal organization and working performance, and has a short production cycle and high efficiency.

Heat treatment process of spray formed 6061 aluminum alloy

Abstract: The heat treatment of spray-formed 6061 aluminum alloy was studied.The effects of solution temperature,aging temperature and aging holding time on the microstructures and mechanical properties were investigated using hardness measurement,tensile test and TEM.The results show that with increasing the solution temperature,the hardness of alloy increases,while the tensile strength,yield strength and elongation first increase and then decrease.The hardness,tensile strength and yield strength of the alloy first increase then decrease with increasing the aging temperature,while the elongation decreases.The hardness,tensile strength and yield strength curves of the alloy are hump-like change with prolonging the aging holding time,while the elongation changes a little and increases only at 17 h.The best heat treatment process of the spray-forming 6061 aluminum alloy is as follows,solution treated at 530 ℃ for 1 h and then aging at 175 ℃ for 8 h.

The Microstructure and Mechanical Properties of Super-High Strength Al Alloys by Spray Forming

Abstract: To analysis the microstructure and properties of super-high strength Al-Zn-Mg-Cu alloys containing Zr ,Ni and Mn, the apparatus of SEM、TEM、and Tensile machine was used. The results show that the microstructure was fine and homogeneous, the phases became finer for the alloys with adding Zr, Mn, Ni than the alloy with Zr only after solid solution. The ultimate tensile strength of the alloy was 850MPa and the elongation was 5% respectively at peak aging.

High-Strain-Rate Superplasticity of Big Grains in Spray Forming Ultrahigh Carbon Steel Contain 1.6wt.%Al(UHCS-1.6Al)

Abstract: Spray forming UHCS-1.6Al material has a refined equiaxed pearlitic structure, which was necessary for high-train-rate superplasticity. During deformation, the cementite particles pin the grain boundaries and prevent the grains growing up. As a result it exhibited excellent high-strain-rate superplasticity, with a peak ductility of 187% occurring at a strain rate of 5*10-3s-1.