Browse

101 - 110 of 111 items :

  • Materials Processing x
  • Materials Sciences x
Clear All
Shape optimization of the modular press body

Abstract

A paper contains an optimization algorithm of cross-sectional dimensions of a modular press body for the minimum mass criterion. Parameters of the wall thickness and the angle of their inclination relative to the base of section are assumed as the decision variables. The overall dimensions are treated as a constant. The optimal values of parameters were calculated using numerical method of the tool Solver in the program Microsoft Excel. The results of the optimization procedure helped reduce body weight by 27% while maintaining the required rigidity of the body.

Open access
Stabilisation problem in biaxial platform

Abstract

The article describes investigation of rolling ball stabilization problem on a biaxial platform. The aim of the control system proposed here is to stabilize ball moving on a plane in equilibrium point. The authors proposed a control algorithm based on cascade PID and they compared it with another control method. The article shows the results of the accuracy of ball stabilization and influence of applied filter on the signal waveform. The application used to detect the ball position measured by digital camera has been written using a cross platform .Net wrapper to the OpenCV image processing library - EmguCV. The authors used the bipolar stepper motor with dedicated electronic controller. The data between the computer and the designed controller are sent with use of the RS232 standard. The control stand is based on ATmega series microcontroller.

Open access
The use of IR thermography to show the mold and part temperature evolution in injection molding

Abstract

This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

Open access
Collision Risk Mitigating System for Light Rail Vehicles(LRV)

Abstract

This piece is dedicated tothedescription of the development of collision risk mitigating system. The proposed concept of control system is designed to enhance safety ofpassengers, a driver and other people in vicinityof light rail vehicles (tramways).The requirements were fulfilled thanks to the application of lidar sensor and feature of vehicle positioning on the track map created basingon precise measurements with the use of satellite navigation systemReal Time Kinematic. The map allows to eliminate errors of system operation and to enhance resistance to unfavorable ambient conditions, i.e.temperature or fog. The system calculates work braking distance for particular vehicle speed. In case of obstacle detection which is closer to vehicle than the calculated braking distance, the driver is informed about a collision risk with a buzzer and optical signalization. The system has already been implemented and tested.

Open access
The Influence of the Type of Coating on the Cutting Tool Wear During Turning Of 316L Austenitic Stainless Steel

Abstract

The paper presents the influence of coatings applied with the use of PVD method on cutting tools on the wear of the tool and compares it with an uncoated P25 cemented carbide plate. During the experiment, two types of TiAlN coatings were used, applied in various proportions, as well as TiN coating. During the tests, the average width of the wear band on the flank face in B VBBzone and the width of KBcrater were monitored. Moreover, the scanning analysis of the tool was conducted in order to determine the intensity of adhesive wear. The lowest values of selected tool wear indicators were found out with the use of TiAlN coating applied in eight layers in the proportions 33/67% -TiN/TiAlN. The scanning analysis proved the highest adhesive wear of the uncoated P25 cemented carbide plate, as well as increased abrasive wear of the flank face and the formation of a crater in comparison with coated plates.

Open access
Journal for Technology of Plasticity
The Journal of University of Novi Sad
Open access
Caracterisation of Titanium Nitride Layers Deposited by Reactive Plasma Spraying

Caracterisation of Titanium Nitride Layers Deposited by Reactive Plasma Spraying

Forming and cutting tools are subjected to the intense wear solicitations. Usually, they are either subject to superficial heat treatments or are covered with various materials with high mechanical properties. In recent years, thermal spraying is used increasingly in engineering area because of the large range of materials that can be used for the coatings. Titanium nitride is a ceramic material with high hardness which is used to cover the cutting tools increasing their lifetime. The paper presents the results obtained after deposition of titanium nitride layers by reactive plasma spraying (RPS). As deposition material was used titanium powder and as substratum was used titanium alloy (Ti6Al4V). Macroscopic and microscopic (scanning electron microscopy) images of the deposited layers and the X ray diffraction of the coatings are presented. Demonstration program with layers deposited with thickness between 68,5 and 81,4 μm has been achieved and presented.

Open access
Experimental Tooling for Contact Stress Measurement in Bulk Metal Forming Processes

Experimental Tooling for Contact Stress Measurement in Bulk Metal Forming Processes

Knowledge of contact stresses in metal forming operations is essential not only for optimal die design, but also for theoretical and numerical analysis of the metal forming processes. Determination of contact stresses can be performed theoretically and experimentally. This paper presents a tool construction with built-in pin-load cells for experimental determination of contact stresses and friction coefficient at upsetting of prismatic specimen with cylindrical dies. This construction allows measurement of contact stresses in any point of the contact surface of specimen, due to adjustable location of pin-load cells. The adjustments are performed by turning cylindrical dies around its own axis in combination with the change of axial position of the specimen. Experimental determination of contact stresses in upsetting of Ck35 prismatic specimens using cylindrical tools was performed at the Laboratory for technology of plasticity, FTN Novi Sad.

Open access
One Contribution to the Friction Investigation in Bulk Metal Forming

One Contribution to the Friction Investigation in Bulk Metal Forming

Friction is resistance to relative motion when one body slides over another. In metal forming operations, both sheet metal and bulk metal forming, friction is undesirable but also unavoidable occurrence. It has negative impact on main process parameters as well as on workpiece quality. In order to obtain accurate results in metal forming experiments or simulations, the precise value of friction has to be known. In this paper several methods for friction evaluations, such as ring test, forward bar extrusion, backward - forward hollow extrusion, twist extrusion are presented and analyzed. A new double backward extrusion model is proposed.

Open access
Selected Applications of Virtual Reality in Manufacturing

Selected Applications of Virtual Reality in Manufacturing

Virtual reality (VR) has become an important and useful tool in science and engineering. VR applications cover a wide range of industrial areas from product design to analysis, from product prototyping to manufacturing. The design and manufacturing of a product can be viewed, evaluated and improved in a virtual environment before its prototype is made, which is an enormous cost saving. Virtual Manufacturing (VM) is the use of computer models and simulations of manufacturing processes to aid in the design and production of manufactured products. VM is the use of manufacturing-based simulations to optimize the design of product and processes for a specific manufacturing goal such as: design for assembly; quality; lean operations; and/or flexibility.

Open access