Solidification of cast iron alloys brings about volumetric changes. This article describes direct measurements of volume changes with an illustration of the analysis of volumetric changes during solidification of cast iron with the use of a specially designed riser combined with a furnace. It provides a discussion on the dilatometer analysis that is generally used to measure linear displacement as a function of temperature for all types of materials, and the problems associated with volume-change measurements. The article presents a graphical representation of a consequence of the anisotropy, where the calculated volume change is illustrated as a function of temperature. It concludes with a review of kinetic of graphite expansion.

Control of grain flow is one of the major advantages of shaping metal parts by rolling, forging, or extrusion. This article shows the effects of anisotropy on mechanical properties. Cylindrical forgings commonly have a straight parting line located in a diametral plane. The alternate classes of parting lines are called either "straight" or "broken" for brevity. Regardless of whether draft is applied or natural, the forging will have its maximum spread or girth at the parting line. Proper placement of the parting line ensures that the principal grain flow direction within the forging will be parallel to the principal direction of service loading. The article reviews the mutual dependence of parting line and forging process. It provides a checklist for the forging designer that suggests a systematic approach for establishing parting line location. Finally, the article contains examples, with illustrations of parting line locations, accompanied by tables of design parameters.

This article describes the general root causes of failure associated with wrought metals and metalworking. This includes a brief review of the discontinuities or imperfections that may be the common sources of failure-inducing defects in bulk working of wrought products. The article discusses the types of imperfections that can be traced to the original ingot product. These include chemical segregation; ingot pipe, porosity, and centerline shrinkage; high hydrogen content; nonmetallic inclusions; unmelted electrodes and shelf; and cracks, laminations, seams, pits, blisters, and scabs. The article provides a discussion on the imperfections found in steel forgings. The problems encountered in sheet metal forming are also discussed. The article concludes with information on the causes of failure in cold formed parts.

Torsion tests can be carried out on most materials, using standard specimens, to determine mechanical properties such as modulus of elasticity in shear, yield shear strength, ultimate shear strength, modulus of rupture in shear, and ductility. This article discusses the torsional deformation of prismatic bars of circular cross-section and torsional response of prismatic bars of noncircular cross-section. It analyzes the elastic deformation, plastic deformation, and the effect of strain rate on plastic deformation. The article describes the theory of anisotropy in plastic torsion and the various components of a torsion testing machine. These include drive system, test section, torque and rotational displacement transducers, and rigid frame.

Zirconium, hafnium, and titanium are produced from ore that generally is found in a heavy beach sand containing zircon, rutile, and ilmenite. This article discusses the processing methods of these metals, namely, liquid-liquid separation process, distillation separation process, refining, and melting. It also discusses the primary and secondary fabrication of zirconium and hafnium and its alloys. The article talks about the metallurgy of zirconium and its alloys with emphasis on allotropic transformation, cold work and recrystallization, anisotropy and preferred orientation, and the role of oxygen. It concludes by providing useful information on the applications of reactor and industrial grades of zirconium alloys.

Electron spin resonance (ESR), or electron paramagnetic resonance (EPR), is an analytical technique that can extract a great deal of information from any material containing unpaired electrons. This article explains how ESR works and where it applies in materials characterization. It describes a typical ESR spectrometer and explains how to tune it to optimize critical electromagnetic interactions in the test sample. It also identifies compounds and elements most suited for ESR analysis and explains how to extract supplementary information from test samples based on the time it takes electrons to return to equilibrium from their resonant state. Two of the most common methods for measuring this relaxation time are presented as are several application examples.