Key Engineering Materials Vol. 910

Abstract: At present the production paradigm undergoes a fundamental change when testing of actual units involving castings manufacturing gives way to digital simulation which allows to overcome constraints intrinsic to the traditional methods of trials and errors. This article presents the work on numerical study and prediction of shrinkage porosity in Nickel alloys castings made by precision casting method for further comparison of simulation results with the size of flaws produced during actual hardware testing.

Abstract: The article presents the simulation of part distortion during laser metal deposition and a comparison of its results with the deposition performed in experiment. A numerical methodological approach to simulation is viewed which involves dividing the deposited material into primitive solids and further heating and cooling of each primitive solid along the deposition trajectory instead of simulating a moving heat source.

Abstract: The paper presents the results of a study of changes in the structure during equal-channel angular pressing (1 and 4 cycles) with a deformation rate of 320 mm/s. It was found that a significant structure refinement of copper M1 and Cu-1.1Cr alloy to an ultrafine-grained state occurs already after 1 ECAP cycle. A predominantly band structure with a transverse size of fragments of ~ 200-300 nm occurs. A specific feature of the structural state is alignment of low-and high-angle boundaries by dislocations and absence of unbonded dislocations in the body of fragments. After 1 cycle of ECAP, practically no dispersed particles are observed in the body of Cu-1.1Cr alloy grains, and the electrical conductivity does not change in this case. The maximum hardening of copper M1 is observed after 4 ECAP cycles-1320 MPa with an electrical conductivity of 89% IACS for Cu-1.1Cr alloy, the maximum hardening is achieved after 1 cycle of ECAP and aging at 450 °C for 1 h-1655 MPa with an electrical conductivity of 77% IACS.

Abstract: The present paper considers the manufacturability of polymer composite material tooling intended for molding and bonding of complex curvature honeycomb sandwich structures. The tooling structure consists of inner and outer shells and glass-fiber-reinforced honeycomb core placed between them. The inner shell is glass-fiber-reinforced plastic based on TEIS-53 molten heat-resistant epoxy-bismaleimide resin and Т-10-14 structural fiberglass.

Abstract: The article presents the results of a single grain scratching simulation of a ceramic workpiece using the smoothed particle Galerkin method. The studies were carried out for 0.1-0.8 μm depths of cut, matching the ductile-brittle transition of ceramics grinding with minimum subsurface damage. The crack depth and scratching force were obtained for scratching speed of 40-140 m/s.

Abstract: The paper proposes an approach to assessing the grinding wheel wear, which includes the wear of grains and pulling them out of the bond, based on fatigue failure under cyclic loads caused by cutting forces, with a period of the order of microseconds. This approach is implemented on the basis of stress life calculation in the ANSYS Fatigue module using loading data obtained from the numerical simulation of grain-workpiece interaction. The simulation results allows to obtain the grain wear area, the level of bond fatigue fracture and the possibility of self-sharpening of the grinding wheel for a given grain size and operation conditions.

Abstract: In this paper, we propose designs of grooving and cutting cutters that have internal channels for supplying coolant under high pressure. Due to the fact that drilling of narrow channels in the cutter body is very problematic, the front part of the cutter, which holds the cutting interchangeable carbide plate, is manufactured by an additive method. The back of the cutter (holder) can be manufactured using traditional methods. The design assumes the use of conventional cutting interchangeable carbide plates (ICP), offered by many manufacturers.

Abstract: A new additive technology for forming channels with galvanic-mechanical coatings is considered. The technological process of combined electroplating and mechanical processing of small diameter channels is compiled. Rational technological modes are defined.

Abstract: This paper aims to use the QFORM software package based on the finite element method with a view to computer modeling the wear process of rolled mandrels of the screw rolling mill MISIS - 130D while rolling stainless steel X12CrNiTi18-9 billets into pipes. The wear properties of the mandrels change as the plugging process occurred under various initial conditions. The results show that the wear rate on the mandrels in the reduction zone is more intense at a higher feed angle and distance between guide shoes. Wear distribution on mandrels surfaces can be improved by adjusting the velocity along the rolling side of the mandrels and replacing them with long fast-moving long mandrels. The simulation which results in this work can be used to predict the properties of working-tool wear, depending on the technical parameters, and rolling mode, which consequently increases the quality of rolling process fabrication products and the service life of tools.

Abstract: The article discusses the influence of the parameters of friction stir welding modes on the formation of the outer surface of the weld and the thickness of the intermetallic layer for the thickness of the welded samples of 3 mm. Changing the rotation speed from 600 rpm to 1000 rpm of the welding tool allows you to control the amount of energy input to transfer the welded material into a superplastic state. The welding speed was varied from 20 mm/min to 80 mm/min. The most optimal mode was for an aluminum and copper alloy with a thickness of 3 mm, a rotation speed of 900 rpm, a welding speed of 25 mm/min, an angle of inclination of 3⁰ at which the mechanical properties of the welded seam approached the most plastic material (aluminum). The article considered thermal cycles measured near the pin from the side of the aluminum and copper alloy. The maximum temperature was 900 K on a copper alloy. The parameters of welding modes also affect the formation of intermetallic layers. If the thickness of the intermetallic layer does not exceed 4-5 μm, then increased values of the mechanical strength of the welded dissimilar joint are observed.