Papers by Keyword: Spinning

Abstract: D406A steel is a medium-carbon low-alloy steel, which has excellent comprehensive mechanical properties. It is widely used in the production of missiles and rocket barrels. In this paper, the spinning forming limit test and the intermediate heat treatment process of ultra-high-strength steel were used to explore the effect of spinning process and heat treatment on the properties of spinning parts. The research results showed that the reduction amount of the material made the material thinning rate approach the limit thinning rate. The final blank wall thickness was reduced from 15 mm to 3.0 mm when the cracking occurred. It was calculated that the material's power spinning limit thinning rate was 80%. The ferrite matrix after spinning showed a streamline distribution characteristic perpendicular to the thinning direction, and the precipitated carbides were uniformly distributed on the surface of the matrix, which had the characteristics of deformation and extension along the streamline. After the heat treatment, the structure of the spinning parts changed continuously. When the structure was quenched and tempered, the martensitic structure can be obtained, and the tempered martensitic structure was smaller. Furthermore a test piece for ultra-high-strength steel spinning technology has been developed, and the solutions discussed for flanging defects in the actual spinning process, and test data for the actual production of ultra-high-strength steel spinning parts accumulated.

Abstract: Spinning is a type of plastic forming in which a tool such as a roller is pressed against a rotating plate or tube to gradually deform the shape and obtain a product with the same shape as the forming die. This processing method has the advantage that it can be processed seamlessly but has the drawback of causing internal defects due to deformation. In this study, the purpose is to obtain basic knowledge about the internal defect generation mechanism in spinning, and to perform cold and hot spinning with high diameter reduction under various conditions on Al-Mg-Si alloy tube. From the experimental results, it was confirmed that the inner defects increased as the diameter reduction ratio increased. It was considered that the main cause of the occurrence of inner defects was that, at a high diameter reduction ratio, the amount of processing was large, so that the increase of material flow led to increase of wall pressure.

Abstract: In this paper, 15% SiCp/2009A1 composites were subjected to multi-pass hot spinning experiments. The principle of the microstructure and properties of the materials was studied with the increase of thinning rate. The microstructures, interfaces, precipitates and their properties of the tube, which were in the states of spinning, spinning and solution heat treatment were analyzed and discussed.The research shows that it is possible to prepare spinning pipe with good shape and smooth surface by taking use of the spinning process of this paper. During the power spinning process, the force of the rotary wheel to the pipe causes the billet to produce two-way deformation, and the axial and tangential grains are obviously elongated and the flow line is formed.There are mainly Al, SiC, CuAl₂ and Mg₂Si phases in the tube, and the spinning deformation does not change the phase composition of the composites, but the SiC distribution can be more uniform and the oxide film on the surface of the aluminum particles is broken, as a result that the oxygen element will cluster at the interface.The solution heat treatment after spinning can greatly improve the yield strength and tensile strength of SiC/Al composites with a slight decrease in plasticity. The spinning process used in this paper can not only form a composite pipe with a smaller diameter and thinner wall thickness, but it can still be applied when the diameter of the pipe blank becomes larger and the wall thickness becomes thicker.Through the research on spinning process and microstructure, the feasibility of spinning process for preparing aluminum matrix composites pipes was explored, which provided technical and theoretical support for the preparation and processing of Particulate reinforced aluminum matrix composites (PRAMCs) pipes for aviation and aerospace applications.

Abstract: The influence of the method of melt spinning on the basis of the Fe-Nd-B system on the amorphous-crystal structure of ribbons and flakes is shown. It is established that the magnetic properties of magnetoplasts depend on the powders particle size, the parameters of mechanic activation during flake milling, the kinetics of formation and growth of Fe₂Nd₁₄B phase nuclei at all stages of their preparation and processing, etc. Isotropic and anisotropic magnetoplasts and sintered magnets with magnetic properties: Br = 0.5-1.25 T, Hc_B = 180-700 kA/m; (BH)_max = 50-280 kJ/m³.

Abstract: A two-step rotary rim-thickening process of disc-like blanks was investigated by FE simulation and spinning experiments. The preforming shape of cross section for first step was designed as trapezium before forming rectangular-shape rim in the second step. The main factors influencing the blank forming in the first step were groove bottom height h₁ and the inclination angle α of the roller. With the increase of h₁ and α of the roller in FE simulation, the workpiece will be more prone to lose stability and cause defects. The forming limit diagram was obtained in first step, including stable forming zone, unstable forming zone and failed forming zone. Considering the stability and efficiency of thickening, four groups of h₁ and α were selected for the second step simulation. Maximum rim thickness (h₂) after second-step forming was 9 mm, obtained by trial and error in FE simulations. The spinning experiments were carried out to verify the validity of numerical simulation.

Abstract: Particulate Reinforced Aluminium Matrix Composites (PRAMCs) have been widely applied in military and civilian areas such as aviation, aerospace, advanced weapon applications and electrical industries due to their good mechanical properties at elevated temperature, low thermal expansion coefficient, excellent wear resistance and low production cost. The main preparation techniques of the PRAMCs include stir casting, powder metallurgy, pressureless infiltration and spray deposition. However, the problems such as low densification and particle cluster encountered in these techniques often reduce the material properties. It has reported that the homogeneity of the distribution of particulate reinforcements in metal matrix can be improved by plastic processing, thus enhancing the material densification. This paper summarized recent progress in the plastic processing methods of the PRAMCs, with an emphasis on the spinning technique. The effects of various process parameters on the material properties were discussed in detail. A summary of research progress on the numerical simulation of plastic processing of the PRAMCs was presented. In the end, an outlook was given on the prospect of the PRAMCs’ development.

Abstract: Polysulfone is synthetic polymer widely used as basic material for dialyzer membrane and hydrophobic so it tends to cause fouling. Cellulose acetate is non-synthetic, hydrophilic polymer which has low tendency of fouling and has good thermal stability and permeability so it is considered as alternative material for hollow fiber dialyzer. A proper hollow fiber can be achieved by setting a proper temperature of coagulation bath along the spinning process. This research aims to understand the effect of coagulation bath temperature variations on the physical characteristic such as pore size, tensile strength, swelling rate and creatinine clearance of cellulose acetate – D-glucose monohydrate hollow fibers. Hollow fibers were fabricated using spinneret at temperature variations 5°C, 10°C, 15°C dan 20°C. Physical characteristics were estimated by doing morphology test using SEM, tensile test, swelling test towards Simulated Body Fluid (SBF) and filtration test towards creatinine. Result revealed that the hollow fibers from 5°C coagulation bath temperature gives the best characteristic and performance with tensile strength 27,421 N mm^-2, pore size 0,0295–0,0858 nm, swelling rate 4,18%, elongation rate 4,4 %, flux rate 1,6032–1,7956 mL cm^-2 min^-1 and creatinine clearance rate 40,14–48,30% so it is potential to be applied as dialyzer membrane.

Abstract: The feasibility of combining spinning, shear forming and flow forming processes has been demonstrated through manufacturing of a representative of a hub component using industrial scale hybrid-forming machine available at the Advanced Forming Research Centre (AFRC). The manufacturing cycle consisted of single to multiple passes of shear forming, spinning and flow forming. The research has proven that the spinning, shear forming and flow forming can be combined using a single machine with a single set of tooling and single process cycle. Circumferential and axial cracking was observed in initial set of trials which were eliminated using a series of experiments. The methodology that was used in these series of trials to remove the cracks/defects that may occur during forming of such component is presented here.

Abstract: The ring frame is the last machine in the technological process to obtain a high quality yarn. The existing machines in textile industry of our country are equipped with drafting assembly suitable for a series of adjustments. Besides this, the ring frames ensure high draft. The efficiency of this high drafts can be justified through their influence on ring frame production. Another technologic parameter that is related on one hand to the yarn quality and on the other hand to the production is the spindles speed. In this paper it is presented a solution for spinning process optimisation for a yarn Nm 52 made by 45% wool and 55% polyester.

Abstract: The reuse of CF-wastes (rCF) is desirable due to the energy-intensive manufacturing, high price and the disposal problem of carbon fibers. It is a challenging process to spin yarn from rCFs in a short staple spinning production line which ensures a much higher strength later in the manufacturing of CFRP (carbon fiber reinforced plastics) parts than that of the parts from rCF-nonwovens or, from short-fiber reinforced injection molded parts. This spinning technology consists of several subsequent processes such as carding, drafting and spinning on a flyer frame. It is possible to produce hybrid yarn up to 2000 tex, which fineness is similar like a roving. The machines used to produce yarn for this purpose were specially modified and adapted, so that the brittle CF can be processed smoothly. Carded and draw frame slivers with different fiber lengths and mixing ratios were produced and later the high-quality hybrid yarn has been spun with different yarn twists.