Minor Cutting Edge Wear in Finish Turning Operations

In finish turning operation, it has already shown, that for the sake of control the dimensional accuracy and the micro-geometry of the worked surface, the wear parameters employed in rough turning operations are not suitable. In the present work the study of wear in fmish turning operations, is carried out, employing a particular groove survey methodology, already proposed in a previous paper, that is based on the techniques of acquirement and processing of images. In order to verify the applicability of the proposed technique two kind of alumina-based inserts and two kind of sintered carbide inserts have been tested. The experimental tests have confirmed the validity of the technique in th…

On the influence of tool path in friction stir spot welding of aluminum alloys

Abstract Friction stir spot welding (FSSW) has been proposed as an effective technology to spot weld the so-called “difficult to be welded” metal alloys. In the paper, a variation of the FSSW process has been considered. A tool path is given after the sinking phase nearby the initial penetration site; in this way a larger welding spot is obtained and more material is involved in the bonding process. The process mechanics of such modified FSSW process is highlighted and the joint strength undergoing tensile tests is considered at the varying both of the assigned tool path and of a few process parameters. Macro- and micro-analyses are made in order to analyze the local material microstructure…

Friction Stir Welding of 3D Industrial Parts: Joint Strength Analysis

In the recent years Friction Stir Welding (FSW) has become an important joining technique since it allows to weld light weight alloys rather difficult to be welded or even “un-weldable” with the classic fusion welding operations. In the paper the authors present the application of the FSW process to the joining of 3D complex shapes typical of the industrial environment. In particular the research was aimed to highlight the joint mechanical strength at the varying of the 3D geometry of the welding line.Copyright © 2006 by ASME

Wear of Ceramic Tools When Working Nickel Based Alloys

In order to improve the toughness of alumina materials, various trials have recently been made. These include toughening by the addition of zirconia and of significant amounts of titanium carbide to ceramic oxide Al2O3 and the more recent use of nitride based ceramics, which have resulted in an increase of fracture toughness and in a significant improvement of ceramic tool performance. Another very recent way of improving ceramic materials consists in adding SiC whiskers to Al2O3 matrix. This composite material is also suitable for machining nickel based alloys. In order to evaluate and to qualify these materials some test cycles have been carried out in continuous cutting conditions, emplo…

Multiobjectives Approach for Process Plan Selection in IMS Environment

Abstract In Integrated Manufacturing Systems (IMS) evaluating the most suitable process plan is a very complex task. Technology, quality, production and market requirements are objectives to be pursued in the selection process, subject to the constraints due to the several part types simultaneously manufactured. The paper proposes a new approach to the process planning selection, based on a possibilistic fuzzy programming model in order to face the vagueness coming from the formalization of the objectives and constraints in the selection problem.

CAD/CAM Integration for NURBS Path Interpolation on PC Based Real-Time Numerical Control

As anybody knows, there is a fundamental difference between the newest CAD system and the conventional Numerical Control. As a matter of fact, almost every CAD Software allows programmers to use parametric 2D or 3D curves, whereas standard Numerical Control cannot perform anything more than linear or circular interpolations. NURBS are the most successful among all the proposed parametric curves, since they allow us to give an exact uniform expression to both the analytical and the free form curves. Nevertheless, this typical characteristic nowadays entails that in CAM systems a tool path is rounded down using a small movements and imposing a maximum acceptable gap. This approach leads up to…

An E-learning Experience in Technical Education

E-Learning is relatively new emerging technology that spans the universities and other institutions. It concentrates on utilizing Knowledge of teachers in a way that academic courses can be delivered anywhere and anytime.

A CAD/CAM oriented Learning Management System

Part program automatic check for three axis CNC machines

Abstract The simulation and verification of NC codes for CNC machining is a very important task. The aim of this work is to limit the number of cutting tests needed to verify the right writing of the part program for a CN milling machine in the intent of saving time, human resources and money. This is obtained through the Boolean operation among solids, in AutoCAD environment, of the volume covered by the tool during the operations ruled by the part program.

NC End Milling Optimization within CAD/CAM System using Particle Swarm Optimization

The authors have been set up an optimization procedure, based on Particle Swarm Optimization (PSO) evolutionary algorithm, that has been enclosed in FeatureCAM, a commercial CAD/CAM software, to automatic determine milling optimal cutting parameters. The Particle Swarm Optimization has been selected because it is very effective to solve optimization problems characterized from complex objective functions and high bonds number. This algorithm also allows to obtain a near optimal solution with a very few iterations and then a computational limited time, characteristic very important to integrate the procedure in a CAD/CAM system.

Tool Path Design in Friction Stir Spot Welding of AA6082-T6 Aluminum Alloys

In the paper, a variation of the Friction Stir Spot Welding (FSSW) process has been considered. In particular, a particular tool path is given after the sinking phase nearby the initial penetration site. The process mechanics was highlighted and the joint strength was considered at the varying of the most relevant process parameters. Furthermore macro and micro analyses were developed in order to highlight the process mechanics and the local material microstructure evolution. The investigated technology appears a promising joining technique in order to develop effective spot joints.

A Web based remote control of CNC machines

Due to the large variety of products in small batch sizes, a modern machining shop floor requires an advanced real-time control system able to both monitor all the features and adapt the manufacturing system to the rapid changes of production capability and functionality. This is especially true when the shop floors are combined with the e-Manufacturing concept. e-Manufacturing is a transformation system which enables the manufacturing operations to achieve a predictive near-zero-downtime performance as well as to synchronize with the management systems through the use of infotronics technologies (i.e., wireless connections, web applications, networking systems, etc.). In recent years, the …

Friction Stir Welding of 3D Industrial Parts

Real-Time Routing Selection in Flexible Manufacturing Systems

Routing flexibility is one of the main peculiarities of Flexible Manufacturing Systems. This paper proposes three methods for real-time routing selection. The first one makes decisions comparing the current workload of machines in each alternative path. The second method considers the current workloads at the bottleneck machines in each allowed route. The third approach makes real-time decisions minimizing a merit index that represents a measure of the still required resource amount. The index is computed by short discrete-event simulation runs. Some case studies evaluate and compare the proposed approaches.

Ceramic materials wear mechanisms when cutting nickel-based alloys

Abstract In this paper the performances of some commercial ceramic inserts when cutting AISI 310 steel are investigated and compared to those of a traditional carbide based tool. The most important wear mechanism in the ceramic inserts is related to the segmented edges of the chips that abrade a notch at the end of the cut zone. Alumina–zirconia inserts are very sensitive to this kind of wear, whereas tools made of Sialon and alumina with SiC whiskers exhibit slightly better performances despite the concomitant chemical wear mechanisms.

A New On-Line Roughness Control in Finish Turning Operation

A new on-line control method for the wear state of sintered carbide tools for finish turning operations is proposed.

Simulation of Milling Machining Process within an Open Source CAD System

To verify NC programs as well to optimize the cutting conditions, it is very important to simulate machining process more precisely. The diffusion of electronic realistic representation systems of mechanical pieces suggests us to use them in order to realize a virtual simulation of the cutting tests for a milling machine Our task was to create a software which can directly read and interpret the part program and display it using a CAD solid modeler which, considering the effective geometry of the tool and of the workpiece, can simulate cutting forces behaviour during a milling process.

Cutting Temperatures Evaluation in Ceramic Tools: Experimental Tests, Numerical Analysis and SEM Observations

The authors propose a multiple approach for the evaluation of cutting temperatures in ceramic tools. The first approach was the experimental evaluation of equitemperature lines, obtained in three-dimensional cutting by employing constant melting point powders scattered on planes parallel to rake face. In the second approach, a numerical finite element analysis was performed. At this step the determination of the percentage of total heat produced in the operation that flows into the tool was considered and, consequently, the temperature distribution within the whole volume of the insert. Finally, the examination of the crater zone with SEM microscopy confirmed the temperature levels as previ…

Machining of Steel with Advanced Ceramic Cutting-Tools

A More Simple G-Code Programming within an Open Source CNC System

In this paper we introduce the utilization of a new CNC programming language, named O-Word, a way to implement several branching routines into the EMC interpreter. It opens new interesting possibilities to programmers who can build subroutines, loops, and conditionals while taking advantage of the interpreter's use of variables and computation. Therefore, it allows us to make pieces describing theirs features instead of tool's movements. We will demonstrate a new complex routine in order to show both the language syntax and its potential for advanced applications.

Tool Path Design in Friction Stir Welding of AA6082-T6 Aluminium Alloy

In the paper, a variation of the Friction Stir Spot Welding (FSSW) process has been considered. In particular, a particular tool path is given after the sinking phase nearby the initial penetration site. The process mechanics was highlighted and the joint strength was considered at the varying of the most relevant process parameters. Furthermore macro and micro analyses were developed in order to highlight the process mechanics and the local material microstructure evolution. The investigated technology appears a promising joining technique in order to develop effective spot joints.