Comparison of Surface Roughness When Turning and Milling

The quality of a machined surface can be described by macro and micro parameters, like the size error, the form and position error or the surface roughness. The task of machining process planning is to find the best machining method and parameters, which ensure the required quality. In this article, the surface roughness in the case of turning and milling technologies is analysed. The effect of the cutting parameters (feed at turning and depth of cut at milling) and the tool parameter (corner radius) are investigated. The results are compared with the theoretical geometric model of surface roughness. In longitudinal turning as well as in constant Z-level milling, the geometric model of surface roughness is similar. The article presents whether the real surface roughness is similar too.

Investigation of ultrasonic-assisted CNC cutting of honeycomb cores

As compared to traditional milling, ultrasonic-assisted cutting of honeycomb core materials has the advantages of small cutting force and superior surface quality. Currently, ultrasonic straight blade V-shaped machining is one of the most efficient roughing processes. The requirement of a processing path to be post-processed based on the processing characteristics of the straight blade cutter is one of the key issues faced while meeting the technological requirements of CNC machine tools for V-shaped machining. A post-processing method of NC code for V-shaped machining of straight blade cutter is proposed in this article. Initially, the V-shaped rough machining process planning is done, followed by the usage of Unigraphics (UG) to output the initial CNC code. Next, the CNC code is executed through the three key technologies of the second arrangement of cutter locations. Later, research is done on information planning of lifting and lowering cutter, along with research on planning of chip breaking toolpath. Eventually, the simulation cutting experiment is carried out through VERICUT. The results demonstrate that the post-processing method can meet the processing requirements.

IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

Decomposition and Sequencing for a 5-Axis Hybrid Manufacturing Process

Hybrid Manufacturing (HM) combining Additive Manufacturing (AM) and subtractive machining (SM) technologies have recently been introduced and have the potential to address the shortcomings of AM, such as the poor surface finish and requires post-processing of the support structures. One such example of an HM machine is the DMG Mori Lasertec 65. These 5-axis HM machines allow for rapid deposition of material during additive manufacturing and address the issues of feature resolution, surface finish, and tolerances by subtractive machining. Additionally, these processes allow for the creation of complex geometries not possible with standard 5-axis machining. Process planning for HM is a reasonably complex manual task and could benefit from automation. Critical steps in process planning are the decomposition of the part into additive and subtractive features, sequencing all features and assigning the tool-paths for these features. This paper presents algorithms for decomposing the part and sequencing the additive and subtractive features in an automated manner, paving the way for a fully automated system for HM. Examples of a wide range of parts demonstrating the capability of the algorithm are presented.

Graph-Based Feature Recognition and Combination Method for Automatic Process Planning System

Generating the Numerical Control (NC) tool path for machining a complex shaped component is highly dependent on the proficiency of a Computer-Aided Manufacturing (CAM) programmer in manufacturing field, although the CAM systems now are highly integrated. A Computer-Aided Process Planning (CAPP) system, which can automatically extract the manufacturing features from the Computer-Aided Design (CAD) model and generate the machining process planning, has been expected for a long time. In this research, a graph-based CAPP system was proposed. It mainly includes four modules, data conversion module, feature classification module, feature combination module and process planning module. The first two modules claim a graph-based feature recognition method, output the recognized manufacturing features which are classified into four classes and defined as specific types. The feature combination module generates different paths to combine manufacturing features from a goal model into raw material shape by four kinds of combination methods corresponding to the four classes. Finally, the process planning module will give a cost estimation of all those paths with the consideration of manufacturing resources and time cost. A relatively optimized machining method and machining sequence will be generated as the output of this proposed system.

Decision-making for multi-criteria optimization of process planning

The objective of this work is to develop a methodology for the automatic generation of optimised and innovative machining process planning that enable aeronautical subcontractors to face current productivity and competitiveness issues. A four-step methodology is proposed, allowing the user to obtain optimised machining ranges that respect his know-how and experience and introduce innovation. This methodology is based on a representation of the decisional behaviour of the user in a given situation as well as in the face of the risk of industrialisation and broadens the formalisation of the performance of a process by taking into account other performance criteria other than machining time or overall cost. A genetic algorithm is used to generate optimized process planning. An AHP method is used to represent the decision-making process. The methodology presents the best processes generated and the use of social choice theory enables it to target the most efficient ranges to be implemented, by integrating a risk criterion to the industrialization.