Vol 38, No 11 (2018)

A pilot production unit for fusible metal powders is considered. The formation of liquid metal particles in a melt generator based on the chamber of a low-thrust rocket engine is described. The systems employed in the proposed unit are itemized, including supply systems for the fuel components and initial powder material; the system for flow-rate measurement; the system for collection of the solidifying metal particles; and the system for automated collection and preliminary analysis of the experimental data.

For the example of a planar 3-RRR mechanism of parallel structure, geometric optimization of the mechanism by the SQP method so as to maximize the theoretical and effective working zone is considered, in the case where passage through singular positions is possible.

The application of the finite-element method in the design of vehicle components consisting of physically nonlinear materials is possible by parabolic approximation of the actual deformation diagram. Taking account of physical nonlinearity permits satisfactory design of the load-bearing structures in vehicles.

The influence of oscillatory smoothing on the residual stress in cylindrical components is investigated by simulation and laboratory experiments. The residual stress is found to depend on the tool supply, the interference, the workpiece speed, the oscillatory frequency, and the tool’s angular position (inclination). The experimental results are in good agreement with the modeling data.

The quality of systems constructed from components that have been produced at enterprises in different locations is considered. A particular sequence of processes is required in order to improve the performance of enterprises involved in the design and production of such systems. That sequence is identified. The basic principles that ensure the quality of such systems are formulated: in particular, compatibility of the components is essential. The constraints associated with the system’s emergent properties must be taken into account.

The chip formation in turning by cutting inserts with balls at the front surface is considered. Chip samples are shown. The use of such cutting inserts is found to decrease vibration in the lathe and to improve the final surface quality.

Methods of formalizing automated base selection in the design of machining processes are analyzed. Such methods are necessary in developing CAD systems for manufacturing processes.

The use of a replaceable polyhedral insert in burnishing is considered. Specifically, the influence of the insert’s configuration on the surface quality of a steel surface after burnishing is studied in complete factorial experiments. The surface quality is assessed in terms of the mean deviation R_a of the profile; the profile’s relative reference length t_p (p = 5%); the mean spacing S_m of the microprojections; and the mean spacing S of local projections. The parameters considered in determining the configuration the burnishing tool (replaceable polyhedral insert) are the interference i, the positional angle φ' of the tool around the vertical axis; and its positional angle ψ around the horizontal axis.

In diffusional surface alloying, gray-iron components of vehicles and machines are heated in contact with oxides of the alloying elements (chromium, titanium, vanadium, and molybdenum). The influence of the sample temperature and holding time in diffusional surface alloying on the thickness of the hardened layer is investigated, on the basis of experiment planning. The models obtained may be used to ensure specified thickness of the hardened layer in diffusional surface alloying, with maximum productivity in both production and repair processes.