Features of Machining Rotor Shafts of Diesel Engine Turbochargers with a Multilayer-Coated Tool

Introduction. The paper presents the results of experimental studies of power parameters when hard alloy steels are machined with tools, the cutting units of which have multilayer hard, heat-resistant and wear-resistant coatings. The obtained data will make it possible to optimize machining hard-to-machine materials. Materials and Methods. The aim of the study is to measure the power parameters of turning products and to create experimental formulas of power parameters for different technological modes. For this purpose, a special measuring multicomponent complex was used to estimate the influence of the mode parameters on the change in the cutting force components. Results. The numerically controlled machine tool was retooled by combining it with a three-component dynamometer and tooling. The cutting unit of the tool was coated with a multi-layer hard, heat-resistant and wear-resistant coating. The tool was equipped with instruments connected to a personal computer for measuring and processing experimental data. According to the results of the study, there have been obtained graphical dependences and empirical formulas, which take into account the influence of the mode parameters on the cutting force components when machining the units of alloy steels of high hardness, heat resistance and wear resistance. Discussion and Conclusion.The study allowed us to obtain experimental formulas of cutting force components for different mode parameters when machining parts by the tool equipped with cutting plates. The plates are coated with multilayer hard and wear-resistant coatings of titanium carbonitride, aluminum oxide and nickel nitride. The coating increases significantly the hardness, heat and wears resistance of the tool cutting unit and provides quality machining.

Power-Based Estimation of Cutting Forces During Turning of Aluminium Biomass Ash Particulate Composite

Aluminum-Biomass Ash Particulate Composite is a reinforced composite material of aluminum and biomass ash particles. The composite offers significant mechanical properties advantage and low-cost advantage because of the use of waste as the reinforcement material and as a result, it is gaining increased industrial attention because of the many advantages they offer over conventional Aluminium Matrix Composites. These materials are mostly accessed on the basis of their mechanical, microstructural and chemical properties with very limited interest on their machinability relative to the base material. The specific cutting force coefficients and cutting forces of the composite were estimated during CNC turning operations and the effects of reinforcement on the machinability responses were studied. In this work, power-based force estimation approach was adopted for this purpose for the first time. This approach is less expensive compared to the dynamometric approach since it relies on adapting existing equipment developed for other purposes. This was done by measuring the electric power of the direct-drive motors of the CNC machine during the turning process and the power measurements were analyzed to obtain the force coefficients. The cutting force components were observed to decrease as the percentage rice husk ash (RHA) reinforcement increased. This agrees with known results for the composite based on the dynamometric approach. Since the cutting force components decrease with increase in reinforcement, it can be deduced that increasing RHA in the Aluminium might reduce friction at the tool-chip interface and extend tool life, in other words, improving machinability. The composite therefore promises to be more cost effective than the base material in machinability terms.

Noncentral forces mediated between two inclusions in a bath of active Brownian rods

Using Brownian Dynamics simulations, we study effective interactions mediated between two identical and impermeable disks (inclusions) immersed in a bath of identical, active (self-propelled), Brownian rods in two spatial dimensions, by assuming that the self-propulsion axis of the rods may generally deviate from their longitudinal axis. When the self-propulsion is transverse (perpendicular to the rod axis), the accumulation of active rods around the inclusions is significantly enhanced, causing a more expansive steric layering (ring formation) of the rods around the inclusions, as compared with the reference case of longitudinally self-propelling rods. As a result, the transversally self-propelling rods also mediate a significantly longer ranged effective interaction between the inclusions. The bath-mediated interaction arises due to the overlaps between the active-rod rings formed around the inclusions, as they are brought into small separations. When the self-propulsion axis is tilted relative to the rod axis, we find an asymmetric imbalance of active-rod accumulation around the inclusion dimer. This leads to a noncentral interaction, featuring an anti-parallel pair of transverse force components and, hence, a bath-mediated torque on the dimer.

Variability in Touchdown Technique and Ground Reaction Force Components during Drop Landing of 107 Healthy Adults

The article's abstract is not available.

Features of virtual duplicate creation of the turning process

The interdisciplinary approach of MC-SUITE implementation of the Industry 4.0 concept and the main requirements for digital models (virtual duplicates) of cyber-physical systems regarding virtual processes compliance to the real ones and the possibility of real-time operation have been described. The main condition for creating an adequate dynamic model of technological processing system (TPS) interaction with the cutting process has been defined and a model for such interaction for the longitudinal turning has been developed. On example of developed turning process structural scheme the possibility of describing the interaction of the TPS input parameters (cutting depth and longitudinal feed) with the output parameters (deformations in the respective directions) due to changes in the model internal parameters in a form of cutting force components have been demonstrated. Such representation of the model allows virtual turning process adjusting by specifying the cutting stiffness and functional dependences for the cutting forces components based on the results of intelligent analytical processing of the monitoring results of the TPS operation.

Axial Position and Speed Control of a Non-Salient Synchronous Axial Self-Bearing Motor using Dynamic Surface Control

The paper focuses on the controller designing for the position and speed of non-salient synchronous type axial self-bearing motors. The motor creates the magnetic field to lift the motor along the shaft and generate rotating torque. Firstly, the motor electro-mechanical relations are analyzed to formulate an accurate mathematical model, then a vector control structure is proposed. The force components control the axial position, and the torque controls the motor speed. Secondly, based on the Lyapunov stability function, the dynamic surface control is used to design position and speed controllers. The system simulation results show that the drive system ensures stability and tracking performance. In addition, the interaction between position and speed loops of the control loop is also negligible

Determination of Coal Cutting Forces Using the Cutting Head of POU-BW/01-WAP Device

The paper presents a method for measuring and recording the forces involved in the coal cutting process. Moreover, a method for visualization of all forces involved in the cutting process was described. In the following part, the construction and principle of operation of a device for determination of forces involved in the cutting process (coal mining), referred to by the author as POU-BW/01-WAP, are presented. Resistance extensometry was used to measure the forces. This is the only device in the world that determines two of three force components that take part in the cutting process. For this purpose, two independent measuring blocks were used, which are strain gauges of force: cutting (Fs) and knife pressure (Fd). In order to register these forces, a real mining knife used in longwall shearer drums was applied – i.e. tangential-rotary. The equipment has the ATEX certificate allowing for operation in real conditions as a device intended for use in potentially explosive atmospheres – in accordance with the directive 94/9/EC. It has received many awards at world fairs for inventions and innovative solutions.

Evaluation of the stressed state of cutting elements of coated end-milling hard-alloy combined cutters

This paper compares stresses arising in the tool material of combined end-milling cutters and their admissible values with the purpose of preventing cutter destruction. The limit stress values of tool materials for the developed endmilling hard-alloy combined cutters having an interfaced cutting part and tailpiece were investigated. The cutting part was made of a tool-grade hard alloy, and the tailpiece was made of structural steel. To determine stresses, simulation modelling was carried out in the ANSYS and Deform software. The cutting force components were found experimentally. It was assumed that lower cutting force components lead to lower stresses in the tool material. This results in a lower probability of tool material destruction. The process of cutting the hard-to-cut stainless steel 12Kh18N10T was considered at the following parameters: a cutting speed of 70 m/min, a cutting depth of 1 mm, and a feeding of 0.1 mm/tooth. The tool material VK8 with no coating and with various coatings promoting the reduction of cutting force components was studied. It was confirmed that a combined end-milling cutter 16 mm in diameter and 92 mm long can be used to cut parts with the same accuracy as using a solid end-milling hard-alloy cutter. An increase in the length of combined cutters decreases the cutting accuracy; however, for lengths 123 and 180 mm, these cutters can be used to manufacture parts applied in general machine building. Therefore, combined end-milling cutters can compete with solid cutters in terms of the manufacturing accuracy and resilience period, which limits the existing applicability of solid cutters. The cost of combined cutters is 10–60% lower than that of solid cutters.

Diamond tool wear monitoring by sensory analysis in milling of absolute black granite

Diamond tools suitable for machining operations of natural stones can be divided into two groups: cutting tools, including blades, the circular blades and the wires, and the surface machining ones, involving mills and grinders, that can be of different shapes. For the stone sawing process, the most adopted tool type is the diamond mill, whose duration and performance are influenced by various elements such as: the mineralogical characteristics of the material to be machined; the working conditions such as the depth of cut, the feed rate and the spindle speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bond formulation hardness. This work allows to indirectly assess the wear of sintered diamond tools by signal analysis (in time and frequency domain) of the cutting force components acquired in the process. The results obtained represent a fundamental step for the development of a sensory supervision system capable of assessing the tool wear and hence to modify the process parameters in process, in order to optimize cutting performance and tool life.