Experience in chemical heat treatment of parts made of powder materials for vaz passenger cars

Every car of the Volzhskii Automobile Plant consists of 1.6 (VAZ-2106) to 4.0 (VAZ-2110) kilograms of parts fabricated from powder materials. By the middle of 1996 the range of these parts (weighing from 1.5 to 600 g) consisted of 150 items. They are fabricated from powders based on iron and copper (119 and 31 items, respectively). Almost half of the iron-base powder parts are subjected to various kinds of surface treatment, namely, carburizing, cyaniding, gas nitriding, and steam oxide treatment. The present paper is devoted to the special features of chemical heat treatment (CHT) of parts produced from iron (steel) powder materials.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 10, pp. 18–21, October, 1996.     

Effect of fine structure of Pb-In solid solutions on their deformation-induced strengthening at low temperatures

The specific features of low-temperature deformation-induced strengthening of Pb-In single crystals have been studied in a wide range of impurity concentrations. It was shown that a change in the strain-rate sensitivity of flow stress in the concentrated solid solution is connected with the inhomogeneous distribution of impurities. Based on the X-ray diffuse-scattering data, it was found that the short-range order of separation type was formed in these alloys; i.e., the lead atoms were randomly arranged and the indium atoms formed clusters whose characteristic size increased with concentration in a range of 1.0–1.9 nm. In the concentrated alloy, the appearance of coarse impurity clusters as strong obstacles for mobile dislocations in comparison with the impurity atoms and forest dislocations causes not only a sharp increase in the flow stress but also a change in the energy of dislocation-dislocation interaction.     

Fuzzy adaptive networks in machining process modeling: surface roughness prediction for turning operations

Due to the complexity of the machine tool structure and the cutting process, the dynamics of machining processes are still not completely understood. This is especially true due to the demand of high-speed machining to increase productivity. In order to model and control these complex processes, new approaches, which can represent complex phenomenon combined with learning ability, are needed. The combined neural–fuzzy approach appears to be ideally suited for this purpose. In this paper, the recently developed fuzzy adaptive network (FAN) is used to model surface roughness in turning operations. The FAN network has both the learning ability of neural network and linguistic representation of complex, not well-understood, vague phenomenon. Furthermore, it can continuously improve the initially obtained rough model based on the daily operating data. To illustrate this approach, a model representing the influences of machining parameters on surface roughness is established and then the model is verified by the use of the results of pilot experiments. Finally, a comparison with the results based on statistical regression is provided.     

Single Treatment of Steel in Fluidized Bed

Results obtained by the author and his coworkers at the Vysokogorskii Mechanical Works in the city of Nizhny Tagil are presented. The effect of single treatment in fluidized bed on the mechanical properties of high-carbon and low-alloy steels is studied and the data are compared with the properties of these steels after toughening. A mechanized flow line for single treatment of parts from steel 40Kh in fluidized bed is described, and designs of electric furnaces/baths with fluidized bed are presented.     

The Cm-Pt (Curium-Platinum) system

Work was supported by the Department of Energy through the Joint Program on Critical Compilations of Physical and Chemical Data, coordinated thorugh the Office of Standard Reference Data (OSRD), National Institute of Standards and Technology. Literature searched through February 1987. Dr. Peterson is the ASM/NIST Category Editor for binary actinide alloys.     

A Finite Element Simulation of the Electroplating Process

This paper describes the development, comparison and validation of both 2-D and 3-D models of the electroplating process in which the current density distribution, generated using the Finite Element Method (FEM), is used together with Faraday's law of electrolysis to determine the local plating depth. Prior to work on industrial components, a preliminary investigation was undertaken on the electroplating of a square copper cathode (work piece) with a parallel lead anode of identical shape. The results described here show good agreement, particularly in 3-D and are considered to validate the model sufficiently for it to be used for electroplating tooling design.     

Intermetallic phase formation in directionally solidified Al−Si−Fe alloy

The present study has been undertaken to better understand the solidification behavior of Al−Si−Fe alloys containing 7wt.% Si and 0.9wt.% Fe, with particular regard to the formation of phase during controlled solidification and influence of growth rates on intermetallic phase selection. The alloys studied were Al-7Si-0.9Fe alloys, which were produced by a modified Bridgman solidification arrangement. These alloys were solidified unidirectionally with different growth rates (1–30mm/min). The solidified microstructure of these alloys consists of the growth of primary aluminum and multiple second phase reactions.