Preface

This book deals with the fabrication processes used to produce metallic products. It is intended primarily for technical personnel who want to learn more about metallic fabrication processes. This book is useful to designers, structural engineers, materials and process engineers, manufacturing engineers, technicians, production personnel, management, faculty, and students.

The first chapter gives an introduction to the processes used at the mill to produce metals and their alloys. Procedures for the primary melting, casting, and hot rolling of steel, aluminum, and titanium are covered. The importance of ladle metallurgy and secondary melting operations, such as vacuum induction melting, vacuum arc remelting, electroslag remelting, and stainless steel refining by argon oxidation decarburization, are emphasized. Both ingot casting and continuous casting are included. Rolling methods covered include hot and cold rolling, along with annealing procedures (batch and continuous).

The second chapter on casting discusses the basics of solidification, casting imperfections, and the important casting methods—sand casting, plaster and shell casting, evaporative pattern casting, investment casting, permanent mold casting, cold and hot chamber die casting, squeeze casting, semisolid metal processing, and centrifugal casting.

The third chapter is on the bulk deformation processes—forging, extrusion, and drawing. The differences between hot and cold working are initially covered. This is followed by a discussion of forging including hammers and presses, die design and materials, lubrication, forging defects, and forging processes. Forging process descriptions are given for open-die forging, closed-die impression forging, hot upset forging, roll forging, high-energy-rate forging, ring rolling, radial forging, isothermal and hot-die forging, precision forging, and cold forging. The chapter concludes with cold and hot extrusion and the various drawing operations.

Sheet metal forming processes (fourth chapter) usually employ hot or cold rolled sheet or strip material that is formed into a desired shape. Topics covered include cutting of plate and flat sheet, die materials for forming, forming lubricants, and the forming processes of blanking, piercing, fineedge blanking and piercing, press bending and press-brake forming, deep drawing, stretch forming, spinning, rubber-pad forming, fluid-cell forming, drop hammer forming, electromagnetic forming, and superplastic forming.

The fifth chapter covers traditional, abrasive, and nontraditional machining processes with an emphasis on conventional machining. Topics include workpiece machinability, dimensional and surface finish requirements, surface integrity, the mechanics of chip formation, tool wear and cutting tool materials, cutting and grinding fluids, machining equipment, machining parameters, and machining forces and power requirements.

The sixth chapter discusses the various heat treatments used to thermally alter the property of the metal. Included are steel heat treatments—annealing, stress relieving, normalizing, spheroidizing, and hardening by quenching and tempering. Direct and interrupted quenching processes are explained. The second section of the chapter discusses the various surface-hardening processes, such as flame hardening, induction hardening, case hardening by carburization, nitriding, and carbonitriding. The third part of the chapter covers precipitation hardening with an emphasis of aluminum alloys. However, precipitation hardening is also used extensively to strengthen magnesium alloys, nickel-base superalloys, beryllium-copper alloys, and precipitation-hardening (PH) stainless steels.

The seventh chapter covers the rather wide topic of surface finishing and coatings. Areas included are cleaning methods, abrasive finishing, polishing and buffing, eletropolishing, mass finishing methods such as barrel and vibratory finishing, phosphate and chromate conversion coatings, electroplating (e.g., copper plating, chromium plating, and cadmium plating), electroless plating, weld overlay coatings, thermal spray coatings, high-temperature ceramic coatings, and chemical vapor deposition (CVD) and physical vapor deposition (PVD).

Powder metallurgy (eighth chapter) is the process of blending fine powdered materials, pressing them into a desired shape or form (compacting), and then heating the compressed material in a controlled atmosphere to bond the material together (sintering). The powder metallurgy process generally consists of four basic steps: powder manufacture, powder blending, compacting, and sintering. Compacting is generally performed at room temperature, and the elevated-temperature process of sintering is usually conducted at atmospheric pressure. Full-density processes are also included. Optional secondary processing is often used to obtain special properties or enhanced precision.

I would like to acknowledge the help and guidance of Karen Marken, ASM International, and the staff at ASM for their valuable contributions.