Material strength issues

Even using a capping material, mechanical strength issues are still a concern. Good adhesion between all layers involved is critical. On the surface poor adhesion at either the metal-cap layer or the cap layer-polymer interfaces can lead to delamination during... 

Vyzovikina, N., Milman, Yu. and Sirko, A. (2002) New high-strength corrosion resistance aluminum alloys, Problems of Corrosion and Corrosion Protection of Materials, Physico-Chemical Mechanics of Materials, spec.issue No.3, 554-558. 

Primary reference materials are issued by the NBS and the user is required to prepare the calibration solutions according to a prescribed procedure. All calibration solutions have an ionic strength of 160 mmol/kg, which actually refers to the ultrafiltered water phase of plasma, a pH between 7 and 8, and have the composition given in Table 1. 

E.A. Chandler, T. Diaz de la Rubia (Eds.), Bodega Bay International Workshop on Multiscale Modeling of Material Strength and Failure, special issue of J. Comput. Aided Mater. Des., vol. 9 (2)... 

Establish competitive bid vendor contracts to identify conceptual designs and materials of construction and have vendors initiate small scale coupon fabrication and testing to identify fabrication and material compatibility issues with a focus on braze fin integrity. Identify accelerated testing to ensure braze base metal compatibility and fin and braze interface strength over mission life. 

Photopolymerized Tooth Restorative Composite Materials, Strength and Microstrueture , D. T. Turner, A. K. Abell, and K. F. Lein-felder, J. Dent. Res., 58, Special Issue A, Abstract No. 666 (1979)... 

Petroleum pipe hues before 1969 were built to ASA (now ANSI) Standard B31.4 for liquids and Standard B31.8 for gas. These standards were seldom mandatoiy because few states adopted them. The U.S. Department of Transportation (DOT), which now has responsi-bihty for pipe-line regulation, issued Title 49, Part 192—Transportation of Natural Gas and Other Gas by Pipeline Minimum Safety Standards, and Part 195—Transportation of Liquids by Pipehne. These contain considerable material from B31.4 and B31.8. They allow generally higher stresses than the ASME Pressure Vessel Code would allow for steels of comparable strength. The enforcement of their regulations is presently left to the states and is therefore somewhat uncertain. 

The objective of this chapter is to address introductory sketches of some fundamental behavior issues that affect the performance of composite materials and structures. The basic questions are, given the mechanics of the problem (primarily the state of stress) and the materials basis of the problem (essentially the state of the material) (1) what are the stiffnesses, (2) what are the strengths, and (3) what is the life of the composite material or structure as influenced by the behavioral or environmental issues in Figure 6-1 ... 

We could go through that same kind of problem analysis for many different structures, and, in the process, design requirements could be expressed for each of them. The most common (Jesign requirements would be expressed in some manner in terms of strength, stiffness, and life, but there are many other issues as well. Whether the material will corrode, for example. Whether it will provide the proper insulation or just the opposite, sufficient conductivity, and so on. There are many, many different types of tasks that we ask a structure to perform. 

The next level is that of shaped catalysts, in the form of extrudates, spheres, or monoliths on length scales varying from millimeters to centimeters, and occasionally even larger. Such matters are to a large extent the province of materials science. Typical issues of interest are porosity, strength, and attrition resistance such that catalysts are able to survive the conditions inside industrial reactors. This area of catalysis is mainly (though not exclusively) dealt with by industry, in particular by catalyst manufacturers. Consequently, much of the knowledge is covered by patents. 

Manson (72,) expanded the concept to the solid state by observing that the strength of composite materials also depended upon the acid-base interaction between continuous and dispersed phases. More directly, Vanderhoff et al. (21) addressed the issue of adhesion of polymeric materials to corroded steel. They synthesized eight corrosion products of iron, and used the interaction scheme developed by Fowkes and Manson first to characterize the iron corrosion products as Lewis acids or bases and then to select polymer vehicles for practical coating systems. Such results were employed to enhance the adhesion of epoxy systems to substrates which were predominantly iron oxide in nature. A good overview of these Issues was presented by Fowkes in 1983 (74). ... 

---