This article discusses the types of adaptive control (AC) systems for metal cutting according to the AC strategies used. These include adaptive control with optimization (ACO), adaptive control with constraints (ACC), and geometric adaptive control (GAC). The article details the milling and grinding systems based on the ACO strategy. It reviews the fundamentals of ACC systems followed by a description of a particular ACC system for a turning operation. The article also describes the basic characteristics of GAC systems and presents a particular GAC system for the turning of cylindrical parts. It examines the issues in the AC systems such as tool wear/breakage. Trends in the AC systems such as variable-gain ACC systems and integration of adaptive control into CAD/CAM/CIM systems are also discussed.

This article discusses the evolution of computer numerical control and direct numerical control for machine tools. It describes the fundamentals and advantages of numerical control (NC) systems. The article reviews the manual or computer assisted off-line programming methods for programming the tools with the aid of the automatically programmed tool language. It also explains point-to-point and continuous-path or contouring of NC systems and the adaptive systems used for NC.

As additive manufacturing (AM) gains maturity as a manufacturing technique for production in many industrial sectors, inspection as a tool for quality control gains importance. This article is focused on the field of dimensional metrology, which is typically concerned with the verification of size, location, form, and surface topography of geometric features. This is split into two categories: geometric (size, location, form) and surface measurement (topography). The article also focuses on applicable inspection technologies, and it discusses the context within digital thread manufacturing. A case study on the Digital Inspection Requirements Enhancing Coverage and Traceability (DIRECT) is also presented.

This article surveys common additive manufacturing (AM) data-acquisition methods, covering preprocess materials characterization in the lab, machine calibration in the field, in-process monitoring during a build, and the postprocess part inspections and tests. The focus is to identify acquisition-related metadata for AM data sets to improve data usability and reusability. Also included in the article are exemplar metadata definitions for a data set acquired from light-scattering-based particle size analysis.

This article describes the basic functions that should be included when considering the relationship of computer-aided design (CAD)/computer-aided manufacturing (CAM) and machining. These include design, analysis, drafting, process planning, part programming, program verification, part machining, and inspection. The article provides information on hardware, data base, interfaces, and benefits of integrating machining with the CAD/CAM system of a manufacturing plant. It also provides an overview of direct, computer and, distributed numerical control, which are devoid of a number of problems inherent in conventional numerical control.

In situ process monitoring includes any technologies that monitor or inspect during an additive manufacturing (AM) process. This article presents the types, process considerations, and challenges of in situ monitoring technologies that can be implemented during an AM process. The types include system health monitoring, melt pool monitoring, and layer monitoring. The article discusses data analysis, and provides an overview of the integration of sensors into AM machines.

Additive manufacturing (AM) provides exceptional design flexibility, enabling the manufacture of parts with shapes and functions not viable with traditional manufacturing processes. The two paradigms aiming to leverage computational methods to design AM parts imbuing the design-for-additive-manufacturing (DFAM) principles are design optimization (DO) and simulation-driven design (SDD). In line with the adoption of AM processes by industry and extensive research efforts in the research community, this article focuses on powder-bed fusion for metal AM and material extrusion for polymer AM. It includes detailed sections on SDD and DO as well as three case studies on the adoption of SDD, DO, and artificial-intelligence-based DFAM in real-life engineering applications, highlighting the benefits of these methods for the wider adoption of AM in the manufacturing industry.

This article provides an overview of the methods used to control aspects of the arc welding process and research associated with the development of closed-loop feedback control of the process. Successful implementation of a closed-loop feedback control system requires sensing, modeling, and control. The article describes the commonly applied sensing techniques for arc welding control: arc sensing and nonimaging and imaging optics. It reviews the physics-based, empirically-derived, and neural network models for arc welding control. The article also discusses the research and development activities that attempt to extend the commercial, welding process controllers, namely, adaptive control, intelligent control, multivariable control, and distributed, hierarchical control.

This article briefly describes the nomenclature, alignment and geometrical considerations, and functional and application requirements of a die set. The die set consists of the shank, guide posts, guide bushings, the punch, and die holders. The article illustrates plate flatness and parallelism in the die set. The testing for abrasion, seizure, and endurance in the die set are discussed briefly. The article concludes with information on die-set recommendations.

Additive manufacturing (AM) is the process of joining materials to make parts from three-dimensional (3D) model data, usually layer upon layer, as opposed to subtractive manufacturing and formative manufacturing methodologies. This article discusses various defects in AM components, such as porosity, inclusions, cracking, and residual stress, that can be avoided by using vendor recommended process parameters and approved materials. It describes the development of process-structure-property-performance modeling. The article explains the practical considerations in nondestructive evaluation for additively manufactured metallic parts. It also examines nondestructive testing (NDT) inspection and characterization methods for each of the manufacturing stages in their natural order. The article provides information on various inspection techniques for completed AM manufactured parts. The various electromagnetic and eddy current techniques that can be used to detect changes to nearsurface geometric anomalies or other defects are also discussed. These include ultrasonic techniques, radiographic techniques, and neutron imaging.

This article is a review of the material extrusion-based ceramic additive manufacturing (MECAM) processes. The discussion begins with details of extrusion with filament and paste, covering the most popular variants of paste extrusion-based MECAM techniques that can be differentiated based on paste type and the method of shape retention of the deposited layer: extrusion freeforming, robocasting ceramic on-demand extrusion, and freeze-form extrusion fabrication. The article then focuses on post-processing considerations and the mechanical properties of sintered ceramic parts. It concludes with information on innovation opportunities in ceramic additive manufacturing, such as incorporating UV-curing and gelation in the process and producing geometrically complex structures from shapeable green bodies.

This article provides an overview of the incremental sheet forming (ISF) process and discusses the process variations of ISF. These variations include single-point incremental forming, two-point incremental forming, and kinematic incremental sheet forming. The article discusses the machines and equipment used in the process and describes the process parameters, process mechanics, and process limits. It illustrates multistage forming strategies and summarizes difficulties that exist with regard to the finite-element process simulation of ISF process. The article also describes hybrid process variations, such as stretch forming and laser-assisted ISF.

Braided structures are unique in their high level of conformability, torsional stability, and damage resistance. This article describes the classifications of braiding such as two-dimensional braiding and three-dimensional braiding. It presents the governing equations for computer-controlled braiding in a table. The article lists the applications of braided fabrics and composites. It discusses the formation, structure, and properties of two-dimensional braid composites and three-dimensional braid composites: the damage tolerance and the impact damage limitation.

The qualification of additive manufacturing (AM) processes and the certification of AM parts is recognized as a significant impediment to the rapid, low-cost deployment of AM manufacturing. The challenges are multifaceted; however, it is an attempt to apply conventional qualification approaches to an inherently different process that has caused the most difficulty. This article examines the conventional qualification methodology and explores how the unique characteristics of AM pose a set of qualification challenges. The extant approach to the qualification of AM processes is described, followed by a discussion on a possible future state.

Finishing refers to a wide variety of processes that generally involve material removal in one form or another to generate surfaces with specific geometries, tolerances, and functional or decorative characteristics. This article discusses four major finishing methods, namely, abrasive machining, electropolishing, mass finishing, and shot peening. In each case, it describes subtypes, process variations, and the associated equipment.