Optimum strength

Where two numbers appear, the first refers to the annealed or solution heat-treated condition, the second to the condition when maximum strength is achieved by cold-working or aging. Otherwise the number refers to the alloy heat-treated for optimum strength. 

Because of constitutional complexity, the exact chemistries of nickel-base superalloys must be controlled carehiUy in order to avoid the precipitation of deleterious topologically close-packed (TCP) phases and extraneous carbides after long-term high temperature exposure. Heat-treatment schedules and thermomechanical treatments in the case of wrought alloys also are important to provide optimum strength and performance. 

The optimum conditions for roasting the clay and the optimum strength (30—60%) of the sulfuric acid used depend on the particular raw material. Finely ground bauxite or roasted clay is digested with sulfuric acid near the boiling point of the solution (100—120°C). The clay or bauxite-to-acid ratio is adjusted to produce either acidic or basic alum as desired and soHds are removed by sedimentation. If necessary, the solution can be treated to remove iron. However, few, if any, of the many methods claimed to be useful for iron removal have been used industrially (29). Instead, most alum producers prefer to use raw materials that are naturally low in iron and potassium. 

Austempering. Lower bainite is generally as strong as and somewhat more ductile than tempered martensite. Austempering, which is an isothermal heat treatment that results in lower bainite, offers an alternative heat treatment for obtaining optimum strength and ductility if the specimens are sufficiently small. 

Filament yams require much lower twist factors for optimum strength than spun yams. These yams are often used as suppHed by the manufacturer and contain producer twist only, which can be as low as 0.25 turns per centimeter. 

Euran Furan resins are thermosetting polymers derived from furfuryl alcohol and Furfural. The cure must be carefully controlled to avoid the formation of blisters and delaminations. To obtain optimum strength and corrosion resistance, furan composites must undergo a postcure schedule at carefully selected temperatures depending upon the laminate thickness. Equipment made with furan resins exhibits excellent resistance to solvents and combinations of acids and solvents. These resins are not for use in strong oxidizing environments. 

Wet curing conditions such as water immersion or moist curing applicable to ordinary cement mortar and concrete is detrimental to latex-modified mortar and concrete. Optimum strengths are obtained by providing a... 

Optimum strength properties and maximum corrosion resistance are required. 

Reinforced thermoplastic parts are generally abraded and cleaned prior to adhesive bonding. However, special surface treatment such as used on the thermoplastic resin matrix may be necessary for optimum strength. Care must be taken so that the treatment chemicals do not wick into the composite material and cause degradation. It may not be a good idea to use chemical surface treatment without first verifying that the treatment does not degrade the substrate. 

Insofar as the catalytic potential of a metal complex is concerned, the formal charge on the metal atom and its ability to form a bond of optimum strength with the incoming substrate are obviously important. We first discuss a way of assessing the charge and the electronic environment around the metal ion. The latter is gauged by the electron count of the valence shell of the metal ion. 

The results listed in Table I indicate that the ply adhesion of the hemicellulose adhesive increased with increasing amounts of borax and sodium hydroxide. The increase in strength, however, leveled off after an optimum was reached. Optimum strength results were obtained with 3.8% borax and 1.3% NaOH on hemicellulose solids. These quantities of additives were subsequently used in all further experiments. 

Unlike unmodified mortars, which require laborious moist curing conditions for optimum strength properties, polymer-modified mortars should be air-cured at ambient temperature and relative humidity. 

But why is the observance of the mixing ratio so important for the adhesives described above As schematically shown in Figure 3.1, in the case of epoxy resin adhesives (Section 4.1), for example, each monomer A needs a monomer B to form the polymer AB. If compared to B, there is too much of the component A, an excess quantity of A remains, which cannot take part in further reactions. The adhesive layer does not cure completely, thus the bond between the adherends will not be sufficiently strong. Taking Figure 3.2 as an example, it becomes clear that the optimum strength is reached at a mixing ratio of A B = 1 1. 

AA. Aluminum Association produced a four-digit system for wrought aluminum alloys and a three-digit system for cast alloys. Examples are alloys 6010 (wrought) and 356 (cast). A temper designation is also required. It follows the alloy designation and indicates the heat-treated or mechanically worked condition of the alloy such as 6010-T6. The T6 suffix indicates the alloy is in the precipitation hardened condition for optimum strength. 

As the silicate solid content is increased in the coated sand, the strength of each junction point attains its maximum value In these higher silicate solids cases, the viscosity of the silicate solution is not a determining factor and additional water has no effect on the strength of the bound sand samples For each sand studied, and each silicate ratio investigated, there is a specific water content of the silicate solution that gives optimum strength properties ... 

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