Search Results for barrel finishing

Cleaning procedures serve to remove scale, tarnish films, and other contaminants that form or are otherwise deposited on the surface of titanium during processing operations such as hot working and heat treatment. This chapter explains what makes titanium susceptible to the formation of scale and how it can be removed via belt grinding, abrasive blasting, and molten salt descaling baths. It also discusses the role of acid pickling, barrel finishing, polishing, and buffing as well as the use of chemical conversion coatings and protective platings.

This chapter covers a wide range of finishing and coating operations, including cleaning, honing, polishing and buffing, and lapping. It discusses the use of rust-preventative compounds, conversion coatings, and plating metals as well as weld overlay, thermal spray, and ceramic coatings and various pack cementation and deposition processes. It also discusses the selection and use of industrial paints and paint application methods.

This chapter is a compilation of terms and definitions related to surface engineering for corrosion and wear resistance.

Iron and steel castings require cleaning as they come out of the shakeout units to remove any burned sand and sand that may remain stuck from the mold. This chapter presents the casting cleaning operation sequence. The sequence includes shot blasting; decoring or removal of cores from castings; degating or removal of runners, gates, and feeders; and flash removal and automation. The chapter also presents the objectives of heat treatment and discusses its processes. The chapter describes product quality control. Quality checks are grouped into three categories: material checks, product checks, and functional checks.

A design modification intended to reduce dowel bolt failures in an aircraft engine proved ineffective, prompting an investigation to determine what was causing the bolts to break. As the chapter explains, failure specimens were examined under various levels of magnification and subjected to chemical analysis and low-cycle fatigue tests. Based on their findings, investigators concluded that the bolts failed due to fatigue compounded by excessive clearances and poor surface finishes. The chapter provides a number of recommendations addressing these issues and related concerns.

Plastic gears are continuing to displace metal gears in applications ranging from automotive components to office automation equipment. This chapter discusses the characteristics, classification, advantages, and disadvantages of plastics for gear applications. It provides a comparison between the properties of metals and plastics for designing gears. The chapter reviews some of the commonly used plastic materials for gear applications including thermoplastic and thermoset gear materials. The chapter also describes the processes involved in plastic gear manufacturing.

This chapter provides a brief history of powder metallurgy from its earliest known uses to present day applications.

This chapter discusses the effect of fiber length and orientation on the strength and stiffness of discontinuous-fiber composites. It also describes several fabrication processes, including spray-up, compression molding, reaction injection molding, and injection molding.

This article presents six case studies of failures with steel forgings. The case studies covered are crankshaft underfill; tube bending; spade bit; trim tear; upset forging; and avoidance of flow through, lap, and crack. The case studies illustrate difficulties encountered in either cold forging or hot forging in terms of preforge factors and/or discontinuities generated by the forging process. Supporting topics that are discussed in the case studies include validity checks for buster and blocker design, lubrication and wear, mechanical surface phenomenon, forging process design, and forging tolerances. Wear, plastic deformation processes, and laws of friction are introduced as a group of subjects that have been considered in the case studies.

This chapter describes the ways in which aluminum has been applied to recreation, with special attention on how its usage has changed the nature of these pursuits. It discusses the usage of aluminum in a variety of sports and sport vehicles.

This chapter explains that the key to forging is understanding and controlling metal flow and influential factors such as tool geometry, the mechanics of interface friction, material characteristics, and thermal conditions in the deformation zone. It also reviews common forging processes, including closed-die forging, extrusion, electrical upsetting, radial forging, hobbing, isothermal forging, open-die forging, orbital forging, and coining.

This article provides a brief description of commercially important thermal spray processes and gives examples of applications and application requirements. The processes covered are flame, wire arc, plasma, high-velocity oxyfuel processes, detonation gun, and cold spray methods. Examples are provided of the applications in aerospace, automotive, and medical device industries as well as the use of thermal spray as an additive manufacturing technique.

Superalloys are susceptible to damage from a variety of surface contaminants. They may also require special surface finishes for subsequent processing steps such as coating applications. This chapter describes some of the cleaning and finishing procedures that have been developed for superalloys and how they work. It discusses the effect of metallic contaminants, tarnish, oxide, and scale and how they can be detected and removed. It also discusses chemical and mechanical surface finishing techniques and where they are used, and presents several application examples.

This chapter discusses the operating mechanism, applications, advantages, and limitations of Brinell hardness testing, Rockwell hardness testing, Vickers hardness testing, Scleroscope hardness testing, and microhardness testing. In addition, the general precautions and selection criteria to be considered are described and details of equipment setup provided.

This chapter describes the various features of the metallurgical microscope. Key concepts are defined such as resolving power, the virtual image, bright- and dark-field illumination, numerical aperture, focal length, image contrast, depth of field, and spherical and chromatic aberration. Metallurgical microscope features such as apochromatic objectives, hyperplane oculars, vertical illuminators, counting reticles, widefield oculars, polarization filters, field diaphragms, interferometers, and tungsten-halogen lamps are explained. The optical system, nosepiece, types of objectives (the lens assembly close to the specimen) and eyepieces, and components of the illumination system are all explained. The last part of this chapter describes special procedures involved in using and calibrating the metallurgical microscope.

This chapter discusses corrosion prevention methods used with aluminum and its alloys. The methods range from relatively straightforward measures, such as proper handling and storage, to advanced early warning corrosion monitoring systems for military aircraft. The chapter summarizes the basic factors that influence design for corrosion resistance and discusses the use of conversion coatings, organic coatings, porcelain enameling, and electroplating. It also discusses corrosion monitoring methods used in chemical processing and refining industries.

This chapter details suitable steels for gas nitriding and discusses conventional gas nitriding, plasma (Ion) nitriding, the ferritic nitrocarburizing processes, gaseous ferritic nitrocarburizing, plasma nitrocarburizing, and the salt-bath ferritic nitrocarburizing processes.

Forging is a deformation process achieved through the application of compressive stresses. During the stroke, pressures and velocities are continuously changing and the initial lubricant supply must suffice for the duration of the operation. Lubricant residues and pickup products also change with time, further complicating the analysis of friction and wear. This chapter provides a qualitative and quantitative overview of the mechanics and tribology of forging in all of its forms. It discusses the effects of friction, pressures, forces, and temperature on the deformation and flow of metals in open-die, closed-die, and impression-die forging and in back extrusion and piercing operations. It presents various ways to achieve fluid-film lubrication in upset forging processes and examines the cause of barreling, defect formation, and folding in the upsetting of cylinders, rings, and slabs. It also explains how to evaluate lubricants, friction, and wear under hot, cold, and warm forging conditions and how to extend die life and reduce defects when processing different materials.