Search Results for cryogenic temperature

This chapter defines low-temperature and cryogenic steels and describes their alloy classifications and their ambient and low-temperature properties. These steels include ferritic carbon and low alloy steels, martensitic low alloy steels, martensitic high alloy steels, and austenitic high alloy steels.

Composite systems for cryogenic applications are discussed in this chapter. This chapter emphasizes filamentary-reinforced composites because they are the most widely used composite materials. It begins with a discussion on the approach to designing and fabricating with low-pressure laminate composites. This is followed by a section providing an overview of the materials in modern cryogenic technology. Then, the chapter describes the effect of cryogenic temperatures on materials properties; it also introduces the various joining techniques developed for composite materials. The effects of radiation on the properties of the materials are covered as well as the processes involved in testing laminates at cryogenic temperatures. Finally, the chapter provides information available on concrete aggregate composites.

This chapter reviews the concepts of fracture mechanics and their application to materials evaluation and the design of cryogenic structures. Emphasis is placed on an explanation of technology, a review of fracture mechanics testing methods, and a discussion on the many factors contributing to the fracture behavior of materials at cryogenic temperatures. Three approaches of elastic-plastic fracture mechanics are covered, namely the crack opening displacement, the J-integral, and the R-curve methods. The chapter also discusses the influence of thermal and metallurgical effects on toughness at low temperatures.

The mechanical properties of a material describe the relations between the stresses acting on the material and its resulting deformations. Stresses capable of producing permanent deformations, which remain after the stresses are removed, are considered in this chapter. The effects of cryogenic temperatures on the mechanical properties of metals and alloys are reviewed in this chapter; the effects on polymers and glasses are discussed briefly. The fundamental mechanisms controlling temperature-dependent mechanical behavior, phenomena encountered in low-temperature testing, and the mechanical properties of some representative engineering metals and alloys are described. Modifications of test procedures for low temperatures and sources of data are also included.

This chapter presents topics pertaining to resistance at cryogenic temperatures: measurement, the resistive mechanisms, and available data. The chapter also presents brief descriptions of the various mechanisms that are operative in producing resistance at low temperatures. The alloys discussed are the nondilute mixtures of metals. An introduction to low-temperature electrical properties of specific metals and alloys is included.

This chapter details low-temperature test procedures and equipment. It discusses the role temperature plays in the properties of typical engineering materials. The effect that lowering the temperature of a solid has on the mechanical properties of a material is summarized for three principal groups of engineering materials: metals, ceramics, and polymers (including fiber-reinforced polymers). The chapter describes the factors that influence the selection of tensile testing procedures for low-temperature evaluation, along with a comparison of tensile and compression tests. It covers the parameters and standards related to low-temperature tensile testing. The chapter discusses the factors involved in controlling test temperature. Finally, the chapter discusses the safety issues concerning the use of cooled methanol, liquid-nitrogen, and liquid helium.

This chapter discusses the structural alloys being used for cryogenic applications in commercially significant quantities. It emphasizes the practical considerations involved in the material selection process and provides the information necessary to make preliminary selections of alloys most suitable for the intended cryogenic application. The chapter provides general information on a class or group of alloys, their representative mechanical and physical properties, and their fabrication characteristics. The materials covered are austenitic stainless steels, nickel steels, aluminum alloys, and other metals and alloys.

This chapter discusses three measurements parameters: temperature, strain, and magnetic field strength. It stresses the measurement of temperature because it is the primary variable in nearly all low-temperature material properties. The chapter contains information on methods and auxiliary materials. Areas of frequent concern, such as thermal contact, heat leak, thermal anchoring, thermal conductivity of greases, insulators, lead wires, ground loops, and feedthroughs are also reviewed. The chapter provides an overview and historical development of temperature scales because the practical use of all thermometers is associated with some approximation of the thermodynamic temperature scale. A short section is devoted to types of temperature measuring devices. The characteristics of commercially available resistance-type strain gauges at low temperatures are stressed.

This chapter provides an overview of the state of the art in high-pressure cold spray equipment, including both spray systems and gas supply systems. The chapter describes the commercial cold spray systems developed by companies such as Cold Gas Technology (CGT) GmbH, Plasma Giken Company Ltd, Impact Innovations GmbH, and ASB Industries. Typical helium and nitrogen gas systems used in high-pressure cold spray processing are reviewed.