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[en] The excess top and bottom parts of the ingot are removed while hot and the ingot is processed to a semi-finished product without prior edge forging. The axial, lowest quality part is removed from the ingot usable part either by hot punching or by cold drilling, and after heating if required, it is forged on a mandrel into a ring-shape semi-finished product. The patented method eliminates the need of forging a handling pin, forging the ingot edges, and reduces the top and bottom crop and loss by burn-off. (Ha)
[en] A new technique for tapered composing transition shaping has been put forward in the process of upset forging with the use of an experimental tool. The results of the upset forging process with the use of a new composing transition has been computer simulated. (paper)
[en] Abstract—The plastic deformation of large disks and hard-to-deform disks on low-power equipment is considered. In comparison with upsetting and flattening by forging, sectional bulk stamping is promising. It permits successive plastic deformation of individual sections of the blank.
[en] This specification covers seven grades of annealed titanium and titanium alloy forgings as follows: Grade F-1 to F-4 unalloyed titanium, Grade F-5 - titanium alloy (6% aluminum, 4% vanadium), Grade F-6 - titanium alloy (5% aluminum, 2.5% tin), and Grade F-7 - unalloyed titanium plus palladium
[en] An experimental investigation into closed-die cold forging of sintered aluminium powder rod- shaped compacts was carried out. Axi-symmetric components were forged from sintered powder preforms with different initial diameter to height ratios. Different compaction pressures, sintering and lubrication conditions were used as variables during the investigations. Detailed observations were made on green/sintered density, compaction defects, forging loads, deformation modes and on the onset of fracture during progressive forging of sintered powder compacts. Experimental results obtained during the investigations have been presented and discussed in detail. (author)
[en] Thixoforming of magnesium AZ91D, where slugs of feedstock material having a rosette structure are heated to a semi-solid state to obtain a globular structure before the material is formed into components in a die casting machine or forging press, was investigated. Experimental thixotropic feedstock of magnesium alloy AZ91 was prepared using CANMET casting simulator with electromagnetic stirring. The paper presents results of the optimized heating of 3-inch diameter and 6 inch long slugs of AZ91D alloy prepared under laboratory conditions. The optimized heating procedure was established to achieve a globular structure with rapid and homogeneous heating of slugs. Forging trials were conducted at MTL/CANMET while die casting of a number of components was carried out at IMI. The optimal casting and forging parameters (slurry temperature, die temperature ram speed and metal pressure) are given. Results on morphological change in the microstructure of the feed stock material during heating are presented. It is shown that the material heated to 580oC should be held at this temperature for 30-90 seconds to achieve globularisation of the primary solid phase without excessive grain growth. The microstructure at various locations in the final product was analyzed. At the optimum casting and forging conditions no significant liquid segregation is observed in the final part. (author)
[en] The design of industrial parts is a clear example of integrative effort that, with a focus of several disciplines, requires a detailed analysis of the different scientific and technological knowledge implied in its conception and development. Inside this performance context, the present work approaches the problem of the project of hot forging parts, proposing the use of criteria of viability and optimization that, based in technical and economical considerations, allow to valuate the adjusting degree of various alternative to the forge process, facilitating with it the selection of the most appropriate. Fixed these bases and with object of shortening times of answer analysis in an application corresponding to parts with revolution symmetry, a computerized system has been introduced that, taking as started data the design of the part, geometrically simulates the forge process, allowing to calculate the adaptation coefficients in those morphologies that are possible according to the criteria of viability criteria. This system also provides a graphic representation of machined part, the forged part and the finished stamp. (Author) 22 refs
[en] Recently, Variable gutter technique has been introduced as a novel method in order to reduce waste materials in closed-die forging processes. In this paper, the capability of this method is investigated for a family of forged parts that the vertical flow of material is the last stage of forming process. As a case study, using the variable gutter technique, the amount of waste material is decreased about 50% for a sample forged part with a local rising. The results of FVM simulations and experiments confirmed the effectiveness of the variable gutter technique in such forging processes. The vertical flow of material in the die cavity (h parameter), as a criterion, for different gutter width and thickness dimensions was examined by FVM simulations. The results shown that the gutter thickness has more effect on vertical flow of material than the gutter width. By decreasing the gutter thickness and increasing the gutter width, the amount of vertical flow of material is increased about 120% and 29%, respectively. Finally, A/H ratio (A = Max width of sectional area of a forged part, H = Max height of a forged part) is proposed as shape complexity factor of a forged part. The results of FVM simulations are indicated that for the ratio of A/H > 2, the variable gutter thickness technique is more effective and can be successfully used to reduce the amount of waste materials.
[en] In metal forming operations, material flow and quality of the product depend on the conditions at the billet/tools interface friction, lubrication, and surface finish. Of these parameters, friction is the most difficult to characterize and its influence is often difficult to predict because of its dependency on a variety of factors. Recently, through a number of investigations conducted, a linear relationship among shear friction factor, dimensionless load and tip distance was obtained. The aim of the present study is to see whether the linear relationship obtained in the previous works was fortuitous or genuine by applying a dimensional analysis introducing processing parameters such as contact pressure, ram velocity, viscosity of the lubricant, load, surface roughness and shear friction factor. From the dimensional analysis based on Buckingham π theorem and the data obtained from the tip test experiment, the present theoretical work derives dimensionless parameters and analysis of variance determines any correlation between the dimensionless parameters obtained. This work reconfirms the theoretical background of the previous experimental findings in the literature