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.

Method for preparing double-scanning and spray forming high-speed steel under purification

Abstract: The invention belongs to the material processing field and relates to a method for preparing double-scanning and spray forming high-speed steel under purification. First, a yttria partially stabilized zirconia ceramic filter is adopted to filter high-speed molten steel that is molten and refined in vacuum atmosphere; before the spray forming of the molten steel, gas washing operation is conducted on a working chamber and an atomizer chamber and high purity nitrogen is filled in the working chamber and the atomizer chamber with gas pressure close to 1atm; the uniformly refined high-speed molten steel is slowly poured into a heated pouring box, through which the molten steel is filtered; and through a draft tube, the molten steel is atomized into melt drip that is deposited on a depositor to form deposition blank. When the temperature of the deposition blank is lower than 200 DEG C, the deposition blank is taken out. In each step of operation of spray deposition, the method reduces harmful ceramic particles and oxides to be mixed in as well as the content of unfavorable elements such as gas, thus not only solving the segregation problem of the high-speed steel, but also improving the purity of the high-speed steel.

Study of the Influence of Silicon Phase Morphology on the Microstructural Stress Distribution in Al–Si Alloys Using Object Oriented Finite Element Modeling

Abstract: Near-eutectic Al–Si alloys were produced by conventional casting and spray forming resulting in microstructural differences due to process dependent cooling rates. The as-sprayed alloy exhibited fine equiaxed Si particles uniformly distributed throughout the matrix in contrast to the as-cast alloy, which exhibited acicular morphology with relatively large needle-like Si particles. The effect of Si morphology on the microstructural stress distribution of the as-cast and as-sprayed alloys was estimated by simulating uni-axial tensile loads on microstructures using Object Oriented Finite Element code (OOF2). Microstructures of the as-sprayed alloy experienced relatively low and uniform stress distribution, while the microstructural stress distribution in the as-cast alloy was significantly influenced by the orientation of the needle shaped silicon particles.

Method for manufacturing additives based on synchronous spray and adhesion

Abstract: The invention discloses a method for manufacturing additives based on synchronous spray and adhesion. The method includes the steps that according to the requirement for the appearance of a part to be formed, a three-dimensional model of the part to be formed is established, and hierarchical processing is conducted according to the machining direction; according to the requirement of the three-dimensional model for the number of base materials and adhesives, base material particles and the adhesives are placed in a powder feeder and an adhesive container respectively, compressed air directly carries the base material particles from the powder feeder without preheating and then conveys the base material particles to a base material spray gun, and meanwhile an adhesive spray gun is controlled to spray the adhesives to conduct adhesive solidification on the base materials; according to the shape of each layer section of the three-dimensional model, relative motion of the spray guns and a platform is controlled, and layer-by-layer multi-material controllable spray forming is conducted; after spray and adhesive forming of the part to be formed, a small number of particle materials which do not adhere to the surface and the internal structure are removed, and a final part to be formed is formed. According to the method, spray of the base materials and spray of the adhesives for adhesive solidification can be conducted at the same time, and the method has the advantages that the base materials are saved, cleaning is easy to conduct, energy is saved and emission is reduced.

Microstructure and property development in spray formed and extruded Al‐Mg‐Li‐Zr alloys for aerospace and autosport applications

Abstract: Low density Al-4Mg-1.3Li-0.4Zr and Al-6Mg-1.6Li-0.4Zr alloys were spray formed and the billets extruded under a range of conditions. The alloy compositions were selected to provide an attractive balance of tensile strength and elongation, without relying on complex post-processing and heat treatments – and are therefore suitable for complex cross section extrusions and free from quench distortion. The as-spray formed microstructures showed fine homogeneous, equiaxed grains with an average size of 10–15 μm. Firstly, a laboratory scale extrusion was carried out to extrude 30 mm diameter billets into 7.5 mm diameter cross-section and to investigate the effects of temperature and ram speeds on microstructural development. The microstructure after extrusion at 400°C was partially dynamically recrystallised with a ∼0.5 area fraction of ∼1 μm grains and the remainder were unrecrystallised elongated grains. Electron backscatter diffraction showed a mixed + double fibre texture. After peak age hardening at 150°C for 96 h, the Al-6Mg-1.6Li-0.4Zr alloy showed a 0.2% proof strength of 495 MPa, a tensile strength of 553 MPa and elongation to failure of 8.5%; Al-4Mg-1.3Li-0.4Zr showed a 0.2% proof strength of 392 MPa, a tensile strength of 476 MPa and an elongation of 10%. Subsequently, large-scale complex cross-section were extruded at ∼400°C. Due to the complexity of the cross-sections and the non-axisymetric deformation, the fibre texture was distorted to FCC rolled Copper and Brass orientations. After a dual-step age hardening treatment of 130°C for 8h followed by 160°C for 8h, the proof strength, ultimate strength and elongations were 340 MPa, 470 MPa and 16% respectively. The combination of relatively simple process steps, high strength and ductility/formability, and low distortion in complex sections demonstrated the strong potential for these low density alloys in aerospace and autosport applications.