Polymer materials are key building blocks of the modern world, commonly used in packaging, automobiles, building materials, electronics, telecommunications, and many other industries. These commercial applications of polymeric materials would not be possible without the use of additives. This article is divided into five sections: mechanical property modifiers, physical property modifiers, biological function modifiers, processing aids, and colorants. It describes three classes of additives that are used to inhibit biological activity, six classes of mechanical property modifiers, three classes of physical property modifiers, and two classes of both colorants and processing aids.

There are many different types of polymeric materials, ranging from glassy to semicrystalline polymers and even blends. Their mechanical properties range from pure elastic with very high strains to fracture (elastomers) to almost pure linear elastic (Hookian behavior) with low strains to fracture (glassy polymers). This article provides an overview of historical development of fracture behavior in polymers. It discusses the processes involved in three fracture test methods for polymers, namely linear elastic fracture mechanics, elastic-plastic fracture mechanics, and post-yield fracture mechanics.

This article reviews the impact response of plastic components and the various methods used to evaluate it.. It describes the effects of loading rate on polymer deformation and the influence of temperature and strain rate on failure mode. It discusses the advantages and limitations of standard impact tests, the use of puncture tests for assessing material behavior under extreme strain, and the application of fracture mechanics for analyzing impact failures. It also develops and demonstrates the theory involved in the design and analysis of thin-walled, injection-molded plastic components.

This article reviews generalized test methodologies for fatigue characterization of polymers and examines fatigue fracture mechanisms in different engineering plastics. It provides detailed micromechanistic images of crack-tip processes for a variety of semicrystalline and amorphous engineering polymers. The article describes fracture mechanics solutions and approaches to the fatigue characterization of engineering polymers when dealing with macroscale fatigue crack growth. It includes mechanistic images for high-density polyethylene, ultrahigh-molecular-weight polyethylene, nylon 6, 6, polycarbonate, and polypropylene. The article describes the micromechanisms of toughening of plastics and uses a macroscale approach of applying fracture mechanics to the fatigue life prediction of engineering polymers, building on the mechanistic concepts. It also describes the factors affecting fatigue performance of polymers.

This article provides the framework for the investigation of bridge failures. It explains the types of bridge loading and presents the regulatory provisions for bridges. Some bridge failures in the U.S. that resulted in significant changes in bridge manufacturing, design, regulation, and/or maintenance are also discussed. In addition, the article provides information on traffic damage and fatigue cracking that result in bridge failures. The need for steels with better fracture toughness in bridge design is also discussed.

This datasheet provides information on key alloy metallurgy, mill product specifications, processing effects on physical and mechanical properties, and applications of high-strength aerospace alloys 2024 and Alclad 2024. It contains tables that list values of tensile property limits for 2024 sheet, plate, and round product forms. Figures illustrate the effect of stretching and aging on toughness of the 2024 sheet and the effect of temperature on tensile properties of 1.0 mm thick Alclad 2024-T3 sheet.

The high-strength plate alloy 2324 is a modification of 2024 alloy composition and process conditions to increase strength in both plate and extrusions without a loss in fracture toughness and other characteristics. This datasheet provides information on key alloy metallurgy, as well as the effects of processing on mechanical properties of this 2xxx series alloy. A comparison of fracture toughness of 2324-T39 to 2024-T351 is presented.

Alloy 295.0 is an Al-Cu-Si alloy suitable for sand casting requiring high strength with ductility and toughness. This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and applications of this series alloy. Room-temperature aging characteristics for aluminum alloy 295.0-F, -T4, -T6, and -T7 are also illustrated.

Alloy 7055 is widely used in the aerospace industry in applications as plate and extrusions. This datasheet provides information on key alloy metallurgy and processing effects on fracture, mechanical, tensile, and compressive properties of this 7xxx series alloy.

This datasheet provides information on key alloy metallurgy and applications of Alclad 2029. It contains tables that present statistically determined mechanical property minimums for Alclad 2029-T8 sheet and plate. The plane stress fracture toughness and fatigue crack growth resistance of alloys 2029 and 2024 are illustrated.

This datasheet provides information on key alloy metallurgy and processing effects on tensile properties and fracture toughness of alloy 7065. Strength-toughness minima for aluminum plate alloy 7065 are presented.

Alloy 2624 was developed by Alcoa as a plate product to replace alloy 2024 and 2324 in applications requiring moderate or high strength and the highest levels of damage tolerance. This datasheet provides information on composition limits, processing effects on physical and mechanical properties, and applications of this alloy. Figures provide comparisons of plane stress R-curves of 2624 with 2024-T351 and 2324-T39 and fatigue crack growth resistance of 2624 with 2024-T351 and 2324-T39.

This article discusses the concepts underlying linear elastic fracture mechanics and elastic-plastic fracture mechanics as well as their importance in characterizing the fracture behavior of the high-strength aluminum alloys. It describes the three methods used for analyzing elastic-plastic fracture, namely R-curve concept, J-integral concept, and crack tip opening displacement method. The article considers the primary measures used to assess the toughness of aluminum alloy castings and wrought alloys: notch toughness, tear resistance, and plane-strain fracture toughness.

Alloy 6156 is an Al-Si-Mg-Cu-Mn weldable alloy, developed for the lower portion of the fuselage, which required a T6 temper strength level and high damage tolerance properties. This datasheet provides information on key alloy metallurgy of this 6xxx series alloy. Fatigue crack growth and material toughness for various thicknesses of alloy 6156 clad T62 are illustrated.

Alloy 6013 is a high-strength Al-Mg-Si-Cu alloy, developed for extruded automotive bumpers. This datasheet provides information on key alloy metallurgy, processing effects on physical, tensile, static and fracture properties, and fabrication characteristics of this 6xxx series alloy.

Alloy 2099 is a third-generation Al-Cu-Li alloy providing an improved combination of strength, elastic modulus, and fatigue crack growth resistance. This datasheet provides information on its key alloy metallurgy and the effects of processing on its mechanical properties.

This datasheet provides information on composition limits, fabrication characteristics, processing effects on physical and mechanical properties, and application performance of thick plate and forging alloy 7085. It presents the specified minimum strength and fracture properties for plate, die, and hand forgings. The datasheet provides a comparison of the strength, fracture toughness, and fatigue crack growth resistance of alloy 7085 plate with those of the legacy plate alloy 7050. It shows tensile yield and ultimate strength at elevated temperature for various temperatures and exposure times for 7085-T7452 die forgings.

This datasheet provides information on key alloy metallurgy and processing effects on mechanical and corrosion performance properties of aluminum alloy 7449. A comparison of toughness and stress-corrosion cracking resistance of alloy 7449 with other alloys is also provided.

The extrusion alloy 7005 is used as extruded structural members, where welded or brazed assemblies require moderately high strength and high fracture toughness. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and fabrication characteristics of this 7xxx series alloy.

Alloy 7097 is a quench insensitive Al-Mg-Zn-Cu-Zr alloy engineered for the most advantageous combination of strength, corrosion resistance, and fracture toughness in thick structural applications. This datasheet provides information on key alloy metallurgy of alloy 7097 and processing effects on mechanical properties of alloy 7097-T7651 plate.