Rafał Talar

Control and Monitoring System for Composite Materials Fabrication Based on PPS Method

Cubic boron nitride (cBN) is commonly used as a cutting tools material for the sake of its high hardness and wear-resistance. But on the other hand cBN, it requires application of an expensive HPHT (High Pressure High Temperature) to avoid the transformation of cBN into low-hardness h-BN, they must be sintered under a pressure of 5 to 6 GPa which substantially increases their production costs. An alternative method, called PPS (Pulse Plasma Sintering), was proposed to decrease the production costs. The PPS significantly decreases the costs of production and therefore it is very attractive for industry. However, automation and dedicated control system for PPS is required to carefully control parameters and hamper the transformation of cBN into hBN. Only the application of automated production line guarantee high-quality of cubic boron nitride samples. The paper discusses the requirements and presents the architecture of the control system dedicated for pulse plasma sintering system.

New Method of Machining Teeth on Unspecialised Machine Tools

In the present work, the authors describe elaborated method of machining teeth with the use of unspecialized machine tools. In the first part of the work the need to develop such a method has been shown and the drawbacks of the known methods have been indicated. Further part of the work describes the process of mathematical modelling the purpose of which was to determine the tool paths during machining. Next, the kinetics of teeth machining with the use of a universal CNC milling centre is presented. Further on, the operation of the algorithm, the user’s interface of the elaborated software and the parameters influencing the machining process have been shown. In the final part of the work, the results of examination of the obtained details have been shown on a gear wheel as an example. The origin of machining errors and their significance has been discussed. In conclusions, summary of obtained results is presented. In last paragraphs, authors discuss machining accuracy of developed method, and application possibilities of described method are emphasised as well. Performed verification proved that developed method is capable of machining gears of quality comparable with these machined with specialised equipment.

Case Study of Thermal Stress Distribution Within Coating Applied on Aluminum Plain Clutch Plate by Thermal Spray Coating Technique

In this paper, information about the durability of friction clutches under high heat conditions was described. As a way to extend their life and performance, thermal spray coating method is proposed. Process of modeling and conducting simulation in FEA (finite element analysis) environment was described. The thermal stress distribution in coating system in relation to the thickness of applied coating was investigated. Conducted simulation allowed to obtain data that presented strong correlation between coating thickness and both maximum value of Huber-Mises reduced stress and stress distribution characteristics within coating. Collected data allowed to evaluate the possibility of application of such coating on an aluminum plain clutch plate that works under high heat and dry conditions. Presented research has proven that design of such coating should especially cosnider coating thickness and thermal stress condiitons, as these factors may have strong influence on relibilty of cluth plates.

Modelling of a contact pressure distribution caused by assembly errors in a spur gear transmission

Following paper presents development and results of finite element structural simulations prepared in order to estimate contact pressure distribution on teeth flanks of gear transmission caused by assembly errors. In first paragraphs, importance of alignment precision of gear transmission components is described. As well, influence of machining and assembly errors on spur gear transmission was introduced. In last part of introduction, innovations in spur gear transmissions assembly processes were described. Process of finite element analysis preparation was presented. Preparation of FEA included development of geometrical model, boundary conditions, discretization of model and definition of external loads. Results of conducted simulations was presented. Especially, contact pressure distribution irregularities caused by misalignment of shafts were examined Obtained data covered correlations between both direction and magnitude of assembly errors with contact stress distribution along tooth length. Conducted tests proved that in case of great-module geared transmission, shaft misalignments in plane which includes gears axes has far lesser influence on contact stress distribution than misalignments in perpendicular direction.

Modelling of spur gear cutting kinematics for multipurpose milling center

This paper describes process of kinematics modelling for new method of gears cutting with milling center. Need for usage of mufti-purpose machines and tools in gear cutting is described. Known methods of gear cutting with machining centers are presented. Disadvantages and problem with known methods are introduced, as well need for new method is mentioned. Preparation of kinematical model of new method of gear cutting is followed by estimation of theoretical roughness of tooth flank. In last paragraphs requirements for machines and tools prepared for application of this method are discussed, as well technological characteristics of this method is presented.

Control and monitoring system prototype for pulse plasma sintering process

Cubic boron nitride is commonly used as a cutting tools material for the sake of its high hardness and wear-resistance. Pulse Plasma Sintering was proposed to decrease the production costs. This method is very attractive for industry, because it significantly decreases the costs of production. The goal of this paper is to present the control system prototype for Pulse Plasma Sintering processes based on programmable logic controller. Only sintering process with carefully controlled parameters allows to restrict the transformation of cBN into hBN and guarantee production of high-quality cubic boron nitride samples. Thus a dedicated control system was developed to control parameters and therefore to improve the production process. This paper presents also a visualisation system which allows the operator to control, monitor and analyze the production process. Prepared application consists of manual and auto operating mode.