Yield strength composites

Alloy Nominal composition, % Tensile strength, MPa " Yield strength, MPa " Elongation, % Electrical conductivity, MH-cm... 

Measurements of stress relaxation on tempering indicate that, in a plain carbon steel, residual stresses are significantly lowered by heating to temperatures as low as 150°C, but that temperatures of 480°C and above are required to reduce these stresses to adequately low values. The times and temperatures required for stress reUef depend on the high temperature yield strength of the steel, because stress reUef results from the localized plastic flow that occurs when the steel is heated to a temperature where its yield strength is less than the internal stress. This phenomenon may be affected markedly by composition, and particularly by alloy additions. 

By adjusting the content of cobalt, molybdenum, and titanium, the 18% nickel steel can attain yield strengths of 1380—2070 MPa (200,000—300,000 psi) after the aging treatment. Similarly, yield strengths of 12% nickel steel in the range of 1035—1380 MPa (150,000—200,000 psi) can be developed by adjusting its composition. 

AHoy no. Nominal composition, wt % Compressive Yield Strength, MPa Ultimate Brinell hardness... 

The alloy name in the United States can include a company name or trademark in conjunction with the composition for alloyed titanium or the strength, ie, ultimate tensile strength for Timet and yield strength for other U.S. producers, for unalloyed titanium. The common alloys and specifications are shown in Table 14. 

UNS Composition, wt % Electrical conductivity, % lACS TensUe strength, MPa 0.2% Yield strength, MPa Elongation in 50 mm, %... 

Steel type ASTM UNS Composition, Yield strength, Idp/im (MPa) Tensile strength, Idp/im (MPa) Elongation, %... 

Sufficient tensile stress. Sufficiency here is difficult to define since it depends on a number of factors such as alloy composition, concentration of corrodent, and temperature. In some cases, stresses near the jdeld strength of the metal are necessary. In other cases, the stresses can be much lower. However, for each combination of environment and alloy system, there appears to be a threshold stress below which SCC will not occur. Threshold stresses can vary from 10 to 70% of yield strength depending on the alloy and environment combination and temperature (Fig. 9.6). 

Many fibrous composites are made of strong, brittle fibres in a more ductile polymeric matrix. Then the stress-strain curve looks like the heavy line in Fig. 25.2. The figure largely explains itself. The stress-strain curve is linear, with slope E (eqn. 25.1) until the matrix yields. From there on, most of the extra load is carried by the fibres which continue to stretch elastically until they fracture. When they do, the stress drops to the yield strength of the matrix (though not as sharply as the figure shows because the fibres do not all break at once). When the matrix fractures, the composite fails completely. 

Consider the peak stress that can be carried by a chopped-fibre composite which has a matrix with a yield strength in shear of d (d = jd ). Figure 25.4 shows that the axial force transmitted to a fibre of diameter d over a little segment 8x of its length is... 

Fig. 18. Yield strengths in three-point bend tests of highly filled composites of polyfvinyl butyral) and silica particles treated with methylsilane and octylsilane coupling agents to varying degrees of surface coverage vs. work of adhesion measured independently using IGC. Redrawn from ref. [90].

No. Material Nominal composition Form aitd condition Yield strength (0.2% offset), 1000 Ib/sq in. Tensile strength, 1000 Ib/sq in. Elongation, in 2 in., % Hardness, Brinell Comments... 

Aluminum drillpipe is generally made of 2014 type aluminum-copper alloy. Composition of this alloy is 0.50 to 1.20% silicon, 1.00% iron maximum, 3.90 to 5.0% copper, 0.40 to 1.20% manganese, 0.25% zinc maximum and 0.05% titanium. The alloy is heat treated to T6 conditions that represent 64 ksi tensile strength, 58 Ksi yield strength, 7% elongation and a Hbn of 135- Aluminum drillpipe generally comes with steel tool joints that are threaded on to ensure maximum strength that cannot be attained with aluminum joints. 

Maraging steel type Ni Nominal composition (Vo) Co Mo Ti Fe Nominal yield strength (MNm- )... 

Apart from that, the smaller the particle size, the stronger the structure formed by filler in the melt (that is, the yield strength of polymer ry is affected). Table 5 below demonstrates how the yield strength of molten polycarbonate composites depends on the size of CaC03 particles. 

AISI type Composition, %i Yield strength, kip/in (MPa)° Tensile strength, kip/in (MPa) Elongation, % Hardness, HB... 

Copper wrought alloy C17410, 7 761 conductivity and yield strength, 7 760t elemental composition, 7 722t Copper wrought alloy C17460 applications, 7 763... 

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