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.

Continuous production technique of spray forming ingot

Abstract: The invention discloses a continuous production process of an injection molding ingot. The production process adopts the organic combination of the injection molding technology and the skew rolling mill assembly continuous rolling technology; the injection molding adopts an atomizing nozzle to atomize alloy fluid flowing from a guide tube into tiny molten drops by inert gas such as nitrogen gas, argon gas, and the like, or the mixture thereof, and the molten drops deposit on a dummy sketch to form the ingot; the dummy sketch and the ingot rotate with the skew rolling mill assembly, and move outwards with the rotation of the skew rolling mill assembly; and the ingot is rolled by an inner skew roll of the skew rolling mill to form a round billet and realize the densifying and continuous production. The continuous production process solves the problems that the density of the existing injection molding ingot is low, and the ingot is restricted by the mechanical structure of an ingot depositor and the inner chamber size of an atomization chamber; and the continuous production process can realize production of infinitely long ingots.

Influence of Hot Isostatic Pressing on the Microstructure and Mechanical Properties of a Spray-Formed Al-4.5 wt.% Cu Alloy

Abstract: Al-4.5 wt.% Cu alloy was spray atomized and deposited at varied spray heights ranging from 300 to 390 mm. The average grain sizes decreased from ~ 29 to ~ 18 μm and a concomitant increase in the hardness and the 0.2% yield strength (YS) with increase in the spray height. The respective hardness values of SF-300, SF-340, and SF-390 are 451 ± 59, 530 ± 39, and 726 ± 39 MPa and the YS are 108 ± 7, 115 ± 8, and 159 ± 10 MPa. The transmission electron micrographs revealed the morphological changes of the Al2Cu phase from irregular shaped to small plate-shaped and then subsequently to spheroidal shape due to high undercooling encountered during spray atomization with increase in spray height from 300 to 390 mm. The porosity of the spray formed deposits varied between 5 to 12%. Hot isostatic pressing of spray deposits reduced the porosity to less than 0.5% without any appreciable increase in grain size. A dislocation creep mechanism seems to be operative during the secondary processing. A comparison between as-spray formed and hot isostatically pressed deposits exemplifies improvement in mechanical properties as a result of elimination of porosity without affecting the fine grain sizes achieved during the spray-forming process.

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%.

Enhanced microstructures and properties of spray-formed M3:2 high-speed steels by niobium addition and thermal-mechanical treatment

Abstract: M3:2 high-speed steel (HSS) billets with or without Nb addition were prepared by spray deposition. The effects of Nb and post-thermal-mechanical processing (decomposition treatment and hot forging), as well as heat treatment, on the microstructure and properties of M3:2 HSS were investigated. The microstructure of the as-deposited M3:2 HSS consisted of equiaxed grains with a mean size of approximately 25 µm and discontinuous plate-like M2C and irregular MC carbides distributed along grain boundaries. 0.5% Nb addition can refine the M2C plates and spheroidize MC carbides. With 2% Nb addition, the refined grains with a mean size of approximately 12 µm and continuous net of M6C and a uniform distribution of NbC carbides were obtained. The decomposition of metastable M2C carbides can be accelerated with 0.5% Nb addition due to the refined size and lower thermodynamic stability of M2C plates. With the increased degree of decomposition of M2C carbide, the M6C and MC carbides became refined and more uniformly distributed after optimal thermal-mechanical processing and heat treatment, which leads to a significant increase in bend strength and toughness.

Method for preparing gradient materials through multi-crucible and multi-nozzle spray forming

Abstract: The invention discloses a method for preparing gradient materials through multi-crucible and multi-nozzle spray forming, which adopts the multi-crucible and multi-nozzle spray forming technology. The method comprises the following steps: firstly, heating and rising the temperature under the protection of inert gas after the surface of a coating substrate is cleaned; secondly, arranging more than one alloy liquid crucible above the coating substrate in sequence, wherein the alloy liquid in each crucible is sprayed and deposited on the surface of the substrate in sequence through being atomized by the high-pressure inert gas to obtain the multi-layered gradient materials. Through the method, the nozzle atomization efficiency and the deposition efficiency are improved, and the continuous preparation of the multi-layered composite materials is realized. The obtained gradient materials have the advantages of low porosity of a deposit perform, fine and uniform organization, better interface binding performance and high material yield.