Key Engineering Materials Vol. 910

Abstract: The article considers the combined processing methods used in the rocket and space technology products manufacture. The technology of obtaining holes in the nozzles of the liquid rocket engine mixing head is presented. The relevance and necessity of using high-tech technologies in the special equipment parts and assembly units manufacture is justified. The ways of ensuring the process stability and technological parameters increasing are shown, which made it possible to expand the application area of dimensional combined processing using the electrode as a tool. The results obtained allow us to expand the production technological capabilities, as well as to improve the technical special equipment products characteristics in mechanical engineering.

Abstract: The article deals with the methods of forming liquid rocket engines parts, in which sheet material is used as a blank. The analysis of the existing methods of processing workpieces with a variable surface profile allows us to conclude that the mechanical method is the most promising type of processing for hole perforation. The drilling holes technology in parts made of sheet blanks is presented. The features of processing non-rigid parts with unpredictable surface fluctuations are considered. The ways of ensuring the stability of the treatment process, increasing the technological indicators, which allowed expanding the area of dimensional machining, are shown. The results of the work contribute to improving the manufacturability of new generations products of equipment, which is important for mechanical engineering.

Abstract: The paper proposes a method for calculating the mode of single-pass arc welding depending on the geometric parameters of the T-fillet weld. The authors reveal the dependence of the residual welding stress level on the welding mode, taking into account the stress concentration due to uneven heating and transverse weld shrinkage. Resulting from the comparison of three modes of single-pass arc welding (manual, mechanized, and automatic), the optimal modes that ensure the maximum lifetime of welded structures are determined.

Abstract: This paper describes a temperature stabilization method in dry metal cutting. Using a hidden phase transfer heat allows to significantly reduce the wear rate. The tool holder design with porous evaporative cooling system is presented. Dependences of tool life of cutters on the cutting speed without cooling and with porous cooling are shown. This approach could be advantageous for the cutting of hard materials (titanium alloy).

Abstract: In this paper presents theoretical and experimental studies of the process of forming the cellular components. The influence on the geometric parameters of cells of different stamping mode is determined by the required number of time steps, it shows the effect of hardening.

Abstract: The article studies the shape errors that occur when cutting styrofoam with a thermo-tool under various cutting modes, and selects the optimal cutting speed.

Abstract: It was carried out the research of variation of foam polystyrene hardness, and was observed the limiting temperature which take enable to cut the foam polystyrene with the use of thermo-tools.

Abstract: Materials with high mechanical properties are increasingly used in modern mechanical engineering in order to enhance the performance and service life of critical parts. Since these are difficult-to-machine materials, serious problems can arise due to low tool life or even with its breakage during mechanical processing. The greatest difficulties are connected with the processing of small-diameter holes, since, for example, breakage of drills or taps occurs when drilling and tapping. It should also be noted that when threading in workpieces made of difficult-to-machine materials, the cutting teeth of the taps are chipped. One of the possible solutions to this problem is the use of physicochemical processing methods, in particular, the transmission of forced ultrasonic oscillations to the tap.

Abstract: In this paper, the effect of tool tilt angle on heat generation and forging force for 1050 aluminum plates, welded by friction stir butt welding, were investigated. Usage of the welding tool with and without pin made it possible to elucidate the particularly reactions of the pin and shoulder on tilt angle variation. For this purpose, tool tilt angle was varied from 0⁰ to 3⁰ under other constant parameters, such as tool geometry and of tool traverse-rotation speed ratio. For the estimation shoulder work pieces interaction the Reynolds lubricant film theory equations were used. The results indicate that the tilt angle is an effective factor on material forging and heat generation behind the pin in the Advancing Side (AS). Recorded peak temperatures were varied from 312 °C to 442 °C in the weld centre.

Abstract: Hadfield steel is widely used in the manufacture of machines and mechanisms operating in harsh conditions. When machining Hadfield steel parts, problems are due to the strain hardening. The article studies the influence of cutting modes on steel hardness, tool thrust and surface roughness when milling Hadfield steel using cutters with replaceable inserts. The experiments were conducted on a milling machining center using high-productivity cutting tools. The optical roughness measuring method was applied. Hardness was measured with a portable hardness tester before and after milling. The article describes experimental results that show the dependence of the output machining parameters on the cutting speed and feed per tooth. The influence of cutting data on tool life in a finish milling operation was identified. The results will help to improve the quality and productivity and increase the tool life in roughing and finishing Hadfield steel parts.