Showing papers on "Spray forming published in 2019"
TL;DR: In this article, a spray forming rapid solidification technology was used to produce a Zn-rich Al-11.3Zn-2.65Mg-1Cu alloy, which was then processed by hot extrusion and heat treatment to T6-temper condition.
33 citations
TL;DR: In this article, a permanent magnetic stirring device was developed and its effect on primary silicon structures and mechanical properties of Al-30%Si alloys were investigated, which enlarged the zone of uniform structure of alloy ingots and significantly refined the primary silicon to a size of 1.3μm.
23 citations
TL;DR: In this paper, a spray-formed Al alloy was synthesized by spray forming followed by hot extrusion, later subjected to (T6 and T74) aging treatments and its mechanical properties were examined.
Abstract: 7055 aluminium (Al) alloy was synthesized by spray forming followed by hot extrusion, later subjected to (T6 & T74) aging treatments and its mechanical properties were examined. To investigate the ballistic behavior of the semi-infinite aluminum alloy target material, ballistic test with two different types of projectiles 7.62 mm soft steel core and 7.62 mm armor-piercing hard steel core projectiles were carried out. Excellent mechanical properties such as; higher strength UTS 708 MPa, fracture to elongation 12.8% and hardness 240 HV were achieved in the T6 condition owing to the MgZn2 phase and Al3Zr strengthening particles. Ballistic performance of the 7055-T6 target was superior to the T74 heat treated condition in terms of depth of penetration, crater diameter, strength, ductility and hardness. The target materials were deformed seriously against armor-piercing hard steel projectile impact as compared to soft steel core projectile. The microstructure was modified within the 1–1.5 mm area from the crater wall. The spray formed Al alloy have a good combination of strength and ballistic performance under the T6 heat treatment condition in comparison of T74 and other alloys produced by conventional forming methods.
21 citations
TL;DR: In this paper, a spray forming method for high-Al TRIP steel is presented to overcome macro-segregation of Mn and Al. The results show that the distribution of stress and strain are more uniform in spray formed steel.
18 citations
TL;DR: In this paper, boron-modified duplex stainless steels were prepared by spray forming using design guidelines provided by thermodynamic calculations, and microstructural investigation revealed the formation of different types of borides embedded in an austenitic-ferritic matrix.
Abstract: In this work, boron-modified duplex stainless steels were prepared by spray forming using design guidelines provided by thermodynamic calculations. Firstly, an investigation of stable phases and phase formation sequence in duplex steels containing high levels of boron was conducted. The calculation indicated that there was an eutectic point at around 1 wt% boron with different primary phase formations upon equilibrium solidification. For hypoeutectic compositions, the primary phase was δ-Ferrite, whereas for hypereutectic a metallic boride (M2B) should form. Additionally, eutectic reactions for both compositions should lead to the formation of borides M2B and M3B2. Secondly, spray forming experiments were conducted based on the thermodynamic calculations. Sample preparation was carried out using a conventional superduplex steel (2507) as starting material. Two different compositions were selected: one hypoeutectic (0.8 wt% B) and one hypereutectic (2.5 wt% B). The microstructural investigation revealed the formation of different types of borides embedded in an austenitic-ferritic matrix. Finally, the wear resistance was evaluated with the dry sand/rubber wheel test and a significant improvement was observed for boron-containing steels in comparison with the same steel without boron. This improvement was attributed to the presence of fine and well-distributed boride particles that protected the austenitic-ferritic matrix from material removal.
16 citations
TL;DR: In this paper, the influence of iron additions on the microstructure and tensile properties of the 319 aluminum alloy processed by spray forming and rotary swaging was investigated, where the spray-formed deposits were rotary-swaged at 573 K with an area reduction ratio of 5:1.
Abstract: The influence of iron additions (0.8, 1.2, and 1.5 wt.%) on the microstructure and tensile properties of the 319 aluminum alloy processed by spray forming and rotary swaging was investigated. The spray-formed deposits were rotary-swaged at 573 K with an area reduction ratio of 5:1. Room temperature tensile tests showed a substantial increase of elongation at fracture (5.5 to 8%) when compared to the values observed for the iron-containing conventionally cast counterpart (0.6%). The high values of elongation at fracture were obtained due to the significant microstructural refinement and decrease of volumetric phase fraction, especially the iron-rich intermetallics, promoted by the combination of spray forming and rotary swaging. Therefore, this processing route significantly reduces the deleterious effect on the ductility caused by the iron content and the presence of β-AlFeSi intermetallic phase in hypoeutectic Al-Si alloy.
15 citations
TL;DR: In this paper, an increase of welding speed from 75 to 150mm/min, the grain size of the nugget zone first decreased and then increased, and the smallest grain size was obtained at 100 mm/min.
11 citations
TL;DR: In this paper, the effect of pouring and tundish temperature in the microstructure of aluminum alloy with high iron content processed by spray forming was analyzed for two different processing conditions: hot swaging and spray forming.
Abstract: Iron has low solubility in solid aluminum and for this reason it can lead to the formation of Fe-rich intermetallic phases (such as β-AlFeSi in Al-Si cast alloys) severely impairing the ductility of the material. Spray forming is an advanced casting process that has been described as a potential technique to highly decrease the β-AlFeSi formation, consequently increasing the ductility. This paper aims to study the effect of pouring and tundish temperature in the microstructure of 319 aluminum alloy with high iron content processed by spray forming. Spray formed ingots and overspray particles were analyzed for two different processing conditions. In order to evaluate the mechanical properties, the spray formed deposits were mechanically conformed by hot swaging. Results showed that the decrease in the β-AlFeSi content strongly depends on the processing conditions. Spray formed deposits processed by hot swaging presented high ductility, allowing a wide range of possibilities to apply casting alloys with high impurity content to more valuable applications beyond the casting industry, therefore decreasing the needs for using primary alloys and contributing to the environment.
11 citations
28 Feb 2019
TL;DR: The spray-forming process of the nano-titanium silicalite (TS-1) zeolite was investigated and optimized in the lab in order to obtain materials with microsphere morphology and superior catalytic activity in cyclohexanone ammoximation on the industrial scale, and the shape of the TS-1 microspheres was as perfect as the Spray-forming samples in thelab.
Abstract: The spray-forming process of the nano-titanium silicalite (TS-1) zeolite was investigated and optimized in the lab in order to obtain materials with microsphere morphology and superior catalytic activity in cyclohexanone ammoximation on the industrial scale. The effects of spray-forming parameters, such as the state of the TS-1 raw material, load ratio, solid content, binder content, and calcination temperature, on the physicochemical and catalytic properties of TS-1 microspheres were investigated in detail. It was interesting to find that the shape of the spray-forming sample formed by wet powders was more intact than the sample formed by dried powders. Furthermore, the spray-forming process was successfully scaled up to a large spray device (LGZ-1000) according to the similarity principle of load ratio, and the shape of the TS-1 microspheres was as perfect as the spray-forming samples in the lab. The similarity principle of the load ratio for the spray-forming of titanium silicate was established and verified for the first time. The spray-forming TS-1 microspheres produced in the industry were used in cyclohexanone ammoximation, and ketone conversion and oxime selectivity were as high as 99.9 and 99.4%, respectively.
9 citations
TL;DR: Al-18Pb and Al-22Pb alloys were processed by a rapid solidification process known as the spray deposition technique and Gaussian or bell-shaped deposits were obtained at a pressure of 10 bar, nozzle to substrate distance of 423 mm and substrate inclination angle of 0° as mentioned in this paper.
Abstract: Al-18Pb and Al-22Pb alloys were processed by a rapid solidification process known as the spray deposition technique. Gaussian or bell-shaped deposits were obtained at a pressure of 10 bar, nozzle to substrate distance of 423 mm and substrate inclination angle of 0°. Deposits obtained from both alloys were warm rolled at a recrystallization temperature of 395 °C. Microstructural analysis of deposits showed that Pb is equally distributed in the Al matrix with 60% thickness reduction. For both alloys, the decrease in thickness percentage resulted in the decrease of hardness values. Porosity was lower in spray deposits of Al-18Pb alloy than the corresponding one from Al-22Pb alloy due to the casting and rolling defects. When the Pb percentage is increased from 18 to 22 in Al-22Pb compared with Al-18Pb, the wear rate increases abnormally. The frequency of wear and coefficient of friction values of Al-22Pb alloy were also higher when compared with those of Al-18Pb alloy.
9 citations
17 May 2019
TL;DR: In this paper, the typical microstructure, mechanical property and wear behaviour of the Al-20Si-3Fe alloy were investigated. And the results showed that both Si particles and intermetallics in the alloy were greatly refined with a size of less than 5 μm.
Abstract: Spray Conform (SC) is an innovative technique, which combines the spray forming and Conform extrusion processes. In this paper, Al–20Si–3Fe alloy has been prepared by this technique. The typical microstructure, mechanical property and wear behaviour of the alloy were investigated. Results show that both Si particles and intermetallics in the alloy were greatly refined with a size of less than 5 μm, and these intermetallics were well aligned in the extrusion direction. Compared with cast alloy, both the mechanical property and wear resistance of the SC alloy have been greatly improved. In particular, the ultimate tensile strength of the alloy is three times more than its conventionally cast counterpart. What's more, high sliding temperature results in a high wear rate but a low frictional coefficient. Wear micromechanics of the SC alloy is abrasive wear and delamination wear at room temperature, and plastic deformation and delamination wear at 200 °C.
TL;DR: In this paper, a review of liquid state processing of aluminium based metal matrix nano-composites along with their microstructures are reviewed critically from open literature and the scope for future research is suggested.
TL;DR: In this paper, an attempt has been made to develop aluminium foam using cenosphere as a space holder by spray forming route, the main process variables were, applied current, gas pressure, and weight fraction of space holders.
TL;DR: In this article, a comparison was made in terms of microstructure, surface morphology as well as isothermal and cyclic oxidation behaviors in the air at 750°C up to 100h and 100 cycles, respectively.
Abstract: To improve the oxidation resistance of near α-titanium alloy IMI834, TiAl-(Cr, Nb, Ta) coatings were deposited by applying high-velocity oxy-fuel (HVOF) and warm spray (WS). Comparison was made in terms of microstructure, surface morphology as well as isothermal and cyclic oxidation behaviors in the air at 750 °C up to 100 h and 100 cycles, respectively. The results show that smoother and less oxidized coatings were deposited by warm spraying. The microstructure of all coatings underwent an appreciable change during the oxidation tests, as in as-sprayed state it occurred in the nonequilibrium state. It was revealed that a small difference in the initial oxidation between the two spraying processes as well as microstructure, the level of porosity and surface roughness significantly influences the oxidation kinetics of the sprayed coatings at high temperature, which should affect the service lifetime as an oxidation-resistant layer for potential applications. After exposure at 750 °C in air, rutile TiO2 was found in addition to α-Al2O3 in the oxide scale formed on the HVOF and warm sprayed coatings. However, isothermal and cyclic oxidation tests of all WS TiAl-(Cr, Nb, Ta) coatings showed improved oxidation resistance of IMI 834 as well as good adherence to the substrate alloy.
11 Oct 2019
TL;DR: In this article, the performance of spray formed tool steel, H13 is investigated in terms of tensile, Charpy impact and fracture toughness properties which are then compared with that of conventional route steel.
Abstract: Spray Forming is a material processing technology in which molten metal is transformed into near net shape solid by capturing spray of atomized metal or alloy onto a moving substrate. In the present work, performance of spray formed tool steel, H13 is investigated in terms of tensile, Charpy impact and fracture toughness properties which are then compared with that of conventional route steel. The analysis was done in two hardness ranges i.e. 44~46 HRc and 48~50 HRc. Tensile test results show that YS, UTS, %El and %RA are similar for both route materials at both hardness ranges. Charpy impact strength obtained for spray formed route steel is lower in all three directions as compared to that of conventional route steel. Fracture toughness results, at higher hardness range, show that KIC value obtained for spray formed route steel is approximately 19.5% & 33.3% lower than that of conventional route steel in LS and TS orientations, respectively. The same at lower hardness range is approximately 28.7% and 24.8% lower for spray formed route steel when compared with that of conventional rote steel in LS and TS orientations, respectively. Metallography and SEM has been done to establish reasons behind the better performance of conventional route steel.
TL;DR: In this paper, the microstructure and properties of M3:2 high-speed steel billets with or without Nb addition were prepared by spray deposition, and the effects of Nb and post-thermal-mechanical processing (decomposition treatment and hot forging), as well as heat treatment, on the micro-structure of the billets were investigated.
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.
TL;DR: In this paper, a spray forming and hot-extrusion procedure was used for aging alloys, followed by two different aging treatment procedures, with different distributions of GP zones and nanoscale precipitates.
Abstract: 7055 Al alloys samples were prepared by spray forming and hot-extrusion followed by two different aging treatment procedures. Their different distributions of GP zones, and nanoscale precipitates η...
TL;DR: In this article, an aluminium syntactic foam has been fabricated using cenosphere space holder by spray forming route, and its wear behavior is investigated, and detailed investigation of reciprocating friction wear has been carried out, and finally, the fretting wear behavior of aluminium foam evaluated against tungsten carbide ball under fretting wearing mode and compared with the as received commercially available aluminium.
Patent•
12 Jul 2019
TL;DR: In this article, a method for improving the strength and toughness of a spray forming high-strength aluminum alloy is proposed, which is suitable for 7000 series and 2000 series aluminum alloy materials containing Zn and Mg elements.
Abstract: The invention relates to a method for improving the strength and toughness of a spray forming high-strength aluminum alloy, and belongs to the field of metal material engineering. A material subcrystalline texture is constructed through an extrusion and forging composite forming technology, and the strength and toughness is improved. The method for improving the strength and toughness of the sprayforming high-strength aluminum alloy is suitable for 7000 series aluminum alloy materials containing Zn and Mg elements and 2000 series aluminum alloy materials containing Cu and Mg elements. The method includes the following steps that (1) alloy ingots made by a spray forming method after being peeled are forged into circular or square forging blanks, the final forging temperature is not lower than 380 DEG C, and the forging ratio is not lower than 10; (2) the forged blanks are subjected to high-temperature annealing, and the annealing temperature is not lower than 420 DEG C; and (3) the annealed forged blanks are extruded into circular or square forged blanks, the extrusion temperature is not lower than 390 DEG C, and the extrusion ratio is not lower than 9. Novel aluminum alloy products produced by the method for improving the strength and toughness of the spray forming high-strength aluminum alloy have excellent strength and fracture toughness, and the fracture toughness can be improved more than twice.
Patent•
05 Jul 2019
TL;DR: In this paper, a heat treatment method for spray forming of a 7055 aluminum alloy is described, which includes the following steps of two-stage solid solution, retrogression low temperature reageing treatment, underaging pretreatment, regression treatment, and low-temperature reaging treatment.
Abstract: The invention provides a heat treatment method for spray forming of a 7055 aluminium alloy. The heat treatment method includes the following steps of two-stage solid solution, retrogression low temperature reageing treatment, underaging pretreatment, regression treatment and low temperature reageing treatment. The two-stage solid solution comprises first-stage solid solution and second-stage solidsolution. Underaging is used as pretreatment before regression treatment, the number of eta phases in an alloy matrix is controlled, only a small amount of the eta phases are generated in the matrix,and thus it is guaranteed that the material has certain yield strength, subsequent regression treatment redissolves most of the GP regions in the matrix into the matrix, and the organization is prepared for a large number of dispersed GP regions precipitated by low temperature reaging. Meanwhile, regression treatment also avoids the aging process needing to take a long time to strengthen the phases in a single GP region to achieve the high strength and toughness of the 7055 aluminum alloy.
Patent•
18 Jun 2019
TL;DR: In this paper, dual-purpose equipment for spray forming and atomization powdering is described, which comprises a machine body, and a gas inlet is arranged in a spray chamber arranged in the machine body.
Abstract: The utility model discloses dual-purpose equipment for spray forming and atomization powdering, which comprises a machine body, and a gas inlet is arranged in a spray chamber arranged in the machine body. When the rotary disc gets close to the nozzle firstly and then rotates and descends step by step, a metal spraying forming body can be manufactured, meanwhile, metal liquid drops which are not formed can form metal powder, when the rotary disc begins to get away from the nozzle, powder manufacturing can be well achieved, and the gate can be used for collecting the metal powder. The metal powder spraying device is used for metal spraying forming and metal powder manufacturing.
TL;DR: In this article, a fine microstructure was observed in LM25 spray deposited Al alloy after warm rolling process due to the expediting cooling and freezing rate of spray deposit and the porosity and Mechanical properties of the warm rolled LM 25 substrate was improved than the spray casted and cold rolled.
05 Apr 2019
TL;DR: In this article, nanocrystalline porous aluminum samples are manufactured using reactive spray atomization following an efficient procedure, and the samples showed the best specific energy absorption density value in compression for aluminum on densification close to 0.06 MJ kg−1 at quasistatic loading, which is the best recorded value for a bulk material according to authors knowledge.
Abstract: In the present work; nanocrystalline porous aluminum samples are manufactured using reactive spray atomization following an efficient procedure. The samples showed the best specific energy absorption density value in compression for aluminum on densification close to 0.06 MJ kg−1 at quasistatic loading, which is the best-recorded value for a bulk material according to authors knowledge. The reasons for such high compression plastic properties are due to a nano-sized intermetallic phase Al2Cu and nano stringers Al2O3 located on the walls of elliptical shape thick wall pores. The aforementioned structural features increased the strength for these samples and enabled absorption of high energy more than other materials. The high performance of the prepared samples and the cheapness of the present method can open new horizons for aerospace and automotive aluminum industries.
Patent•
12 Mar 2019
TL;DR: In this paper, the authors provided a heat treatment process of a 7055 aluminum alloy, which consists of three stages: spray forming, extruding, and annealing the F-state 7055 alloy.
Abstract: The invention provides a heat treatment process of a 7055 aluminum alloy. The heat treatment process of the 7055 aluminum alloy comprises the steps of S1, adopting the following components in percentage by weight: 7.6 percent to 8.4 percent of Zn, 1.8 percent to 2.3 percent of Mg, 2.0 percent to 2.6 percent of Cu, 0.08 percent to 0.25 percent of Zr, and the balance Al, and obtaining a 7055 aluminum alloy blank through a spray forming process; S2, extruding through hot processing; and S3, annealing the F-state 7055 aluminum alloy so as to supplement aging heat treatment. Compared with an existing 7055 aluminum alloy, the tensile strength of the 7055 aluminum alloy obtained through the process method provided by the invention is represented through a room temperature metal material tensile experiment; the stress corrosion cracking resistance and the machining performance are represented through conductivity; the tensile strength, the stress corrosion cracking resistance and the machiningperformance are greatly improved; and the combination property is superior to the existing 7055 aluminum alloy.
TL;DR: In this article, a Si-Al alloy prepared by spray forming process is investigated, and experimental results show that fine and homogeneous grain structure is obtained in as-deposited alloy.
Abstract: A novel Si-Al alloy prepared by spray forming process investigated in this paper. Experimental results show that fine and homogeneous grain structure is obtained in as-deposited alloy. In addition,...
01 Jan 2019
TL;DR: In this article, high Zn-containing aluminum (Al) alloy AA7034 was prepared by spray forming rapid solidification technique, and studied for microstructural development and mechanical properties during subsequent hot extrusion and heat treatment processing.
Abstract: High Zn-containing aluminum (Al) alloy AA7034 was prepared by spray forming rapid solidification technique, and studied for microstructural development and mechanical properties during subsequent hot extrusion and heat treatment processing. It is found out that microstructure after spray forming is composed of equiaxed grains with an average grain size of about 40 μm; however, porosity appears in the spray-formed material. The hot extrusion results in the elimination of microporosity and alignment of microstructure along the extruded direction. The intermetallic compound MgZn2 is detected as a main secondary phase, in an expansion form Mg(Zn,Cu,Al)2, at the spray-formed and extruded states as discovered by XRD; however, impurity phase Al7Cu2Fe is revealed additionally through EDS analysis. The alloy exhibits excellent strength at the peak-aged condition (T6) with Vickers microhardness and tensile strength values of 218 and 808MPa, respectively; which is ascribed to the increased volume fraction of hardening precipitates because of extra Zn-dissolution in the spray forming process.
01 Aug 2019
TL;DR: In this article, a spray conform (SC) technique consisting of the spray forming and Conform extrusion was used for Al-5.72Zn-2.36Mg-1.66Cu (7075) alloys.
Abstract: The commercial Al-5.72Zn-2.36Mg-1.66Cu (7075) alloys were prepared by the spray Conform (SC) technique consisting of the spray forming and Conform extrusion. The extrusion ratio (ER) was selected as the variable parameter to study the influence mechanism on the microstructures and properties while keeping the other parameters unchanged. The microstructures and properties were investigated by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and tensile tests. Concretely, the changing rules of the grains, second phases, tensile strength and elongation with ER were researched respectively. Results indicate that a fine equiaxed grain microstructure with low level of segregation and porosity was achieved by SC. And the intergranular and intragranular phases were fine and homogeneous before and after retrogression and re-aging (RRA). The dispersion and tensile strength are positive to ER, but the grain size (GS) is inverse. Meanwhile, the elongation increases firstly and then decreases with increasing ER.
Patent•
10 Sep 2019
TL;DR: In this paper, a spray-forming method was used for the preparation of an AlSi20Fe5Ni2 aluminum alloy blank, which reduced energy consumption, environmental pollution, and the production cost.
Abstract: The invention provides a preparation method of an AlSi20Fe5Ni2 aluminum alloy blank. The preparation method comprises the following steps that by mass percent, pure aluminum, an aluminum silicon intermediate alloy, an aluminum iron intermediate alloy and an aluminum nickel intermediate alloy are prepared into raw materials according to the ratio of Al to Si to Fe to Ni being 73:20:5:2; the raw materials are smelted in a medium frequency induction electric furnace, heat preservation and standing are carried out for 20 min to 30 min after the raw materials are melted, and a melt is obtained; themelt is subjected to slag removal and degassing; and the melt obtained after slag removal and degassing is poured into a tundish, after standing is carried out, the AlSi20Fe5Ni2 ingot blank is prepared by spray forming, and residual AlSi20Fe5Ni2 alloy powder is formed. Energy consumption is reduced, environmental pollution is reduced, and the production cost is reduced. Raw materials of ordinarypowder metallurgy are mostly formed by mixing several kinds of elementary substance element powder, the risk of uneven mixing exists, a spray forming technology can be used for preparing the alloy powder with uniform compositions, and raw material component matching does not need to be carried out.