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This work analyzes the manufacturing process of an electron-beam additive form by heating as a result of remelting the supplied filler wire as a control object. Control actions and output values are designated that can be used in constructing a control systems with feedback. A mathematical modeling technique is used to study heat transfer in a nonstationary formulation, taking into account the influence of the latent heat of fusion. The transient processes of temperature changes were studied at points, whose values can be used to estimate the extension of the weld pool and the degree of metal overheating. An analysis of the results of computational experiments is carried out, and the range of variations of control actions are shown. The possibility of an independent temperature control in the range of the beam and the extension of the liquid bath is also justified. Recommendations are given for the technical implementation of the system and the option of implementing local regulators, types of sensors, and their installation.

The importance of developing an automated technique for measuring spatial current density distributions of process electron beams is shown. It has been proven that immediate methods based on directly measuring the electron beam current components are of the main interest for constructing monitoring and control systems in electron beam-based process installations, because it is only these methods that can provide reliable information about the spatial distribution of current density. Experimental investigations of spatial current density distributions for electron beams with power capacities up to 6 kW have been carried out. The distributions obtained by the probe method are analyzed, and their deviations from the normal distribution function and axial symmetry are revealed. The limitations of the probe method based on the heat flux density and beam power are determined, and an express method for measuring the current density radial distribution over the electron beam cross section is proposed, which is based on using the direct edge method and on numerically processing the time dependences of the current. A scheme for quantifying the radial distribution of the electron beam current density is given. The possibility of applying the proposed technique for measuring the characteristics of beams with a power density up to 1.8∙104 W/cm2 using a copper collector has been experimentally confirmed. It is shown that the developed technique is necessary for mathematically reconstructing the current density volume distribution using the basic principles of electronic optics.

A complex method for analyzing the processes in the systems of indirect cathode heating for electron- beam welding guns is proposed. The necessity of considering the electron-beam formation process in a cathode assembly with predetermined geometric characteristics is justified for calculating the distribution of the heat-flux density over the main-cathode surface. The typical distribution of the heat-flux density over the surface of the main cathode, which is heated via electron bombardment using a spiral wire heater, is analyzed. A method for calculating the temperature distribution over the structural elements of a typical cathode assembly is described, and the calculation results are analyzed. The influence of the nonuniformity of the electronbeam- current density distribution over the heated surface of the main cathode and the heat dissipation on the temperature and emission-current-density distributions on the working surface of the main cathode is considered. The advantages of the proposed method in comparison with existing idealized mathematical models and its suitability for solving problems of designing various electron guns are demonstrated.

An express method of direct measurements of the current density distribution of axially symmetric electron beams is proposed. It is shown that use of the technique is urgently needed to improve the reproducibility of the results of electron-beam processing. Comparative analysis of existing methods to measure the parameters of electron beams used for technological purposes is carried out. A technique to restore a radial distribution of electron beam current density as well as a device to implement the technique is developed. The results of radial distribution recovery are analyzed in the case in which the initial distribution is given in the form of a model function of normal distribution. An algorithm to determine estimated sizes of the area within which spatial distribution discretization is carried out is developed. Based on analysis of the experimental dependences, it is shown that the suggested numerical method can be applied to all types of axial-symmetric distributions. The nature of errors occurring after distribution function recovery is analyzed. A technological projection of express diagnostic systems for the processing electron beams is made taking into account parameters of the existing element base.

The structure, contents, and operations of electrical equipment, which are parts of a test bench for investigating the characteristics of technological electron guns, are reviewed. A list is given of critical problems that were solved with the equipment under which the basic requirements for system control and data acquisition were designed. Based on the classification of the control and recorded signals, the characteristics of input–output modules of digital and analog signals are defined. Taking into account the features of the equipment, standardized circuit solutions were developed that provide acceptable accuracy for control and signaling, as well as trouble-free operation of a computerized data acquisition system. The use of modem solutions providing galvanic insulation by optical transmission channel technology for both digital and analog signals is discussed. A method of selection of specialized microchips on the parameters of control and measurement signals is shown. Recommendations on the use of measuring complex for research and design of control systems of electron-beam welding installations are provided.

A method of designing electron guns based on the method of parametric analysis and optimization is offered. The criteria of selection of variable parameters—the radius of the spherical surface of the gate electrode and the position of the center of the sphere with respect to the cathode—have been justified. It has been proven that taking due account of the technical limitations of materials and the chosen design allows reducing the task of designing the electron gun to the classical optimization problem. An example of calculating the characteristics of the prototype electron gun using the proposed method is given. Analysis of the results of computational experiments has allowed recommendations to be worked out for the developers of welding electron beam guns in the form of parametric dependences and design algorithms.

An experimental technique for the acquisition of current-density distributions of continuously operating electron beams with an electron energy of 60 keV is proposed. The measurement results for different cross-sectional areas of the beam with a power of 2.1 kW and a current density around 1 × 105 A/m2 are given.

A method for selecting electron-beam welding (EBW) conditions is developed for specific equipment, thickness, and material of a product. The results can be used for calculating and predicting the welding parameters to reduce the time for preparing products for EBW and the material costs.