A Review of Advances in Modeling of Conventional Machining Processes: From Merchant to the Present

This paper presents a review of recent advances in modeling and simulation of conventional metal machining processes, which continue to dominate a significant part of all machining processes, and in recent years, the need for predictive models for machining processes has grown in importance in the digital manufacturing age. Significant advances have been made in modeling the mechanics of cutting in conventional machining, driven by industrial need and enabled by rapid advances in computational power. The paper surveys the state-of-the-art in analytical and numerical modeling of conventional metal machining processes with a focus on their ability to predict useful performance attributes including chip geometry, forces, temperatures, tool wear, residual stress, and microstructure. Also included in the review is a discussion of the industrial use of modeling and simulation tools for conventional machining. Additionally, the practical applicability, implementation benefits, and methodological limitations of conventional machining process modeling have been examined. The paper concludes with a summary of future research directions in modeling and simulation of conventional metal machining processes.

TECHNOLOGY OF BROACHING – RESEARCH OF THE ROUGHNESS AND MACHINE CAPABILITY

The work deals with the technology of metal machining with a focus on the technology of broaching the internal shaped surfaces. The design of the drawing tools is a tool with several cutting edges, whereby the final shape of the inner shaped surface is made for one rectilinear movement of the tool. The cost of broaching tools is higher. For these reasons, the broaching technology is suitable for series production. One part of the paper covers the research of the achieved roughness of the internal grooves when changing the cutting environment, an emulsion was used instead of oil. The second part involves the use of statistical methods in the technology of broaching internal contoured surfaces. The research is focused on the machine capability. The results of measuring the accuracy of the tolerated dimension of the inner holes after broaching are used as input values to this statistic.

The Rise or Decline of Craft Trades? Evidence from Czech Republic and Poland

Entrepreneurial activity in the field of craft professions is an integral part of national economies. The aim of the authors is to prepare an overview article, which would simultaneously compare selected business activities in the Czech Republic and Poland in the field of craft trades with an emphasis on young people and their employability in the labour market. In line with the aim of the article, the authors identified four research questions, which they answered based on the analysis of secondary data. They drew data from databases of statistical offices, ministries and associations. Data were processed using a descriptive statistics apparatus. In the Czech Republic, interest in the study of crafts has stagnated for a long time. In recent years, the number of graduates of craft apprenticeships has been growing. Crafts in the field of mechanical and electrical engineering are preferred, e.g. car mechanic, repairman, mechanical locksmith, electrician. Decrease in the number of graduates is recorded in the food and most construction professions. After finishing the apprenticeship, graduates often leave their field. In Poland, most companies operate in the field of trade and repair of motor vehicles. Measured by the number of graduates, the predominant field is the machinery industry, wellness professions and professions in the food industry. The interest among young people in the studied craft trades is declining in most fields, the field of metal machining shows a growing trend. It is also necessary to confirm the craftsman's expertise with a master craftsman’s certification. It is desirable to expand the possibilities of educating pupils and students in a real work environment. It is important that mutual communication between the worlds of practice and education is functional and effective.

A Survey on AI-Driven Digital Twins in Industry 4.0: Smart Manufacturing and Advanced Robotics

Digital twin (DT) and artificial intelligence (AI) technologies have grown rapidly in recent years and are considered by both academia and industry to be key enablers for Industry 4.0. As a digital replica of a physical entity, the basis of DT is the infrastructure and data, the core is the algorithm and model, and the application is the software and service. The grounding of DT and AI in industrial sectors is even more dependent on the systematic and in-depth integration of domain-specific expertise. This survey comprehensively reviews over 300 manuscripts on AI-driven DT technologies of Industry 4.0 used over the past five years and summarizes their general developments and the current state of AI-integration in the fields of smart manufacturing and advanced robotics. These cover conventional sophisticated metal machining and industrial automation as well as emerging techniques, such as 3D printing and human–robot interaction/cooperation. Furthermore, advantages of AI-driven DTs in the context of sustainable development are elaborated. Practical challenges and development prospects of AI-driven DTs are discussed with a respective focus on different levels. A route for AI-integration in multiscale/fidelity DTs with multiscale/fidelity data sources in Industry 4.0 is outlined.

Needs, Requirements and a Concept of a Tool Condition Monitoring System for the Aerospace Industry

In this paper, we describe the needs and specific requirements of the aerospace industry in the field of metal machining; specifically, the concept of an edge-computing-based production supervision system for the aerospace industry using a tool and cutting process condition monitoring system. The new concept was developed based on experience gained during the implementation of research projects in Poland’s Aviation Valley at aerospace plants such as Pratt & Whitney and Lockheed Martin. Commercial tool condition monitoring (TCM) and production monitoring systems do not effectively meet the requirements and specificity of the aerospace industry. The main objective of the system is real-time diagnostics and sharing of data, knowledge, and system configurations among technologists, line bosses, machine tool operators, and quality control. The concept presented in this paper is a special tool condition monitoring system comprising a three-stage (natural wear, accelerated wear, and catastrophic tool failure) set of diagnostic algorithms designed for short-run machining and aimed at protecting the workpiece from damage by a damaged or worn tool.

Metal Machining—Recent Advances, Applications, and Challenges

Though new manufacturing processes that revolutionize the landscape regarding the rapid manufacture of parts have recently emerged, the machining process remains alive and up-to-date in this context, always presenting itself as a manufacturing process with several variants and allowing for high dimensional accuracy and high levels of surface finish [...]