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.

Spray forming method of insert

Abstract: PROBLEM TO BE SOLVED: To provide a technique for producing a high-performance insert which is not only more cost-effective but is unlimited in terms of chemical properties or in terms of a capability to incorporate a ceramic material. SOLUTION: This method forms the sheet insert by thermal spraying of a bulk material. This method has (a) a stage of preparing a mandrel which is a mandrel having the external dimension not larger than the desired internal dimension of the desired insert and has a means for separating the bulk material sprayed from the mandrel, (b) a stage of forming a bulk composite material having a density of at least 99% by thermal spraying one or more kinds of iron or nickel alloy in the presence of a controlled atmosphere and (c) a stage of forming the discrete sheet insert shapes by cooling the bulk material, then removing such material from the mandrel and slicing the material described above for fitting into the final products.

Study on the Properties of Spray Formed Tool-Die Steel

Abstract: The T15 high speed steel (HSS) spray formed (SF) billets were manufactured using a twin-atomizer spray forming facility at Beijing Institute of Aeronautical Materials (BIAM) AVIC, China. The billets were then hot isostatically pressed (HIP) following hot forge (HF) and heat treatment (HT). The as-spray formed billet is integrally dense and has a high relative density of >98%, and the macrostructure is free of macrosegregation. The microstructure consists of polygonal grains of 20µm with tempered martensite inside the grains and refined carbides uniformly distributed along the grain boundaries. Hardness and three-point bending properties were also measured. The spray formed materials was comparable to those made by powder metallurgy in terms of microstructure uniformity, hardness and bending property.

Microstructure and mechanical properties of Al-nano ZrO2 composites produced by casting route

Abstract: Aluminum metal matrix composites (AMCs) are regarded as candidate materials for aerospace and automotive applications owning to their superior properties, such as high specific modulus specifically at high temperatures, good strength and low wear rates. AMCs have been prepared by liquid metal route such as pressureless infiltration, squeeze casting, stir casting, spray forming, etc. Each of these processes has their own advantages and limitations. The choice of the fabrication techniques is dictated by production cost, process efficiency, the quality desired in the product and their applications. AMCs cast from the liquid state are of interest because of their relatively low processing cost and ease in manufacturing. In the present project, Aluminum A356 and zirconia nano particles were selected as raw materials. Zirconia nano particles were founded to be a promising candidate due to its high hardness, high modulus of elasticity and excellent thermal stability. Samples of composites was made at different amount of zirconia's particles (0, 1.5, 2.5, 5vol %) and temperature of casting were 800, 850 and 950°C. Microstructure of composite specimens was examined using SEM and optical microscopy. Chemical composition was investigated by XRD method. Physical properties such as density and porosity were determined by Archimedes and image analyzing methods. Mechanical properties such as tensile strength, hardness and toughness were determined. The experimental results show that the mechanical properties like tensile strength and hardness markedly improved by adding zirconia nano particles. The maximum was for samples with 5vol% of nano particles were casted at 850°C. Fracture toughness decreased by addition of zirconia nano particles.

Laser beam welding with hypereutectic AlSi filler material

Abstract: For laser welding of AlMgSi (6xxx) alloys filler alloys are commonly required to reduce the hot cracking susceptibility by rising the silicon content in the weld pool to a non critical value. For narrow weld pools obtained e.g. in welding with high brightness lasers, this is often difficult to achieve. The use of hypereutectic Al-Si filler materials might be helpful; however these fillers are not readily available in the form of thin wire.In the present work, hypereutectic Al-Si filler alloys with up to 30% (by weight) Si and additional grain refiners were produced by spray forming. These were processed into strip material, and the effect on hot cracking susceptibility of the weld metal was demonstrated using the delta-test.Furthermore, filler wire was produced from spray formed AlSi18 material with additional Ti-B grain refiner. The 1.2 mm wire was continuously fed during laser welding with a thin disc laser. A strong gradient of the silicon concentration was observed between the top and the root regions of the weld, indicating a lack of vertical transport of alloying elements from the filler within the melt pool. Thus an alternating magnetic field was applied to stir the melt, and it was demonstrated that a supercritical silicon concentration and a homogeneous distribution were achieved in all regions of the melt pool.For laser welding of AlMgSi (6xxx) alloys filler alloys are commonly required to reduce the hot cracking susceptibility by rising the silicon content in the weld pool to a non critical value. For narrow weld pools obtained e.g. in welding with high brightness lasers, this is often difficult to achieve. The use of hypereutectic Al-Si filler materials might be helpful; however these fillers are not readily available in the form of thin wire.In the present work, hypereutectic Al-Si filler alloys with up to 30% (by weight) Si and additional grain refiners were produced by spray forming. These were processed into strip material, and the effect on hot cracking susceptibility of the weld metal was demonstrated using the delta-test.Furthermore, filler wire was produced from spray formed AlSi18 material with additional Ti-B grain refiner. The 1.2 mm wire was continuously fed during laser welding with a thin disc laser. A strong gradient of the silicon concentration was observed between the top and the root regions...

Influences of a Hot-Working Process on the Microstructural Evolution and Creep Performance of a Spray-Formed Nickel-Based Superalloy

Abstract: A new third generation nickel-based powder metallurgy (PM) superalloy, designated as FGH100L, was prepared by spray forming. The effects of hot isostatic pressing (HIP) and isothermal forging (IF) processes on the creep performance, microstructure, fracture, and creep deformation mechanism of the alloy were studied. The microstructure and fracture were characterized by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The coupled HIP and IF process improved the creep performance of the alloy under the creep condition of 705 °C/897 MPa. As for both the HIPed and IFed alloys, the creep process was dominated by the accumulation of dislocations and stacking faults, cutting through γ′ precipitates. The microstructural evolution was the main factor affecting the creep performance, which mainly manifested as coarsening, splitting, and morphology change of γ′ precipitates. Both the creep fractures of the HIPed and IFed alloys indicated intergranular fracture characteristics. In the former, wedge-shaped cracks usually initiated at the trigeminal intersection of the grain boundaries, while in the latter, cavity cracks generate more easily around the serrated curved grain boundary and carbides.