Relaxation resistance

Fig. 11. Comparison between the stress relaxation resistance at 150°C, precipitation hardened alloys A, C172—TH02, and B, C7025—TM02, and C, a...

It is possible to speak about the influence of material substructure of a spring on operational characteristics by spring camber research data, relaxation resistance under cyclic loads, fatigue life test and the failure stress values. 

INCONEL allay X-TM Age-herdenable alley with good corrosion and oxidation resistance. Excellent relaxation resistance. 73.0 7.0 15.5 Ti 2.5 A NR X A NR G-E G-E G-E A G-E... 

Carboxyl ACM with much unproved compression set, compression stress relaxation resistance, and heat resistance while maintaining 30°C low-temperature flexibility, has been developed and named Nipol AR-12 by Zeon Corporation. A comparison of this grade with a standard ACM as well as a low swell AEM-G in Table 5.8 indicates that it will function very well as an improved replacement for AEM-G or standard ACMs [15]. 

One of the most useful features is an optimization subroutine. When a process has several responses to be measured (e.g., tensile strength, modulus, stress relaxation, resistance to heat/fluids, and flex life), the analysis of each response will result in... 

The Maxwell and Voigt models of the last two sections have been investigated in all sorts of combinations. For our purposes, it is sufficient that they provide us with a way of thinking about relaxation and creep experiments. Probably one of the reasons that the various combinations of springs and dash-pots have been so popular as a way of representing viscoelastic phenomena is the fact that simple and direct comparison is possible between mechanical and electrical networks, as shown in Table 3.3. In this parallel, the compliance of a spring is equivalent to the capacitance of a condenser and the viscosity of a dashpot is equivalent to the resistance of a resistor. The analogy is complete... 

This effect of concentration is particularly pronounced with irregularly shaped particles. A possible explanation of the variation in the specific resistance is in terms of the time available for the particles to orient themselves in the growing cake. At higher concentrations, but with the same approach velocities, less time, referred to as particle relaxation time, is available for a stable cake to form and a low resistance results. 

Weathering. Articles fabricated from FEP are unaffected by weather, and thek resistance to extreme heat, cold, and uv kradiation suits them for apphcations in radar and other electronic components. For example, after 15 years of solar exposure in Florida, the tensile strength (73) and light transmission (96%) of a 25-p.m thick film was unchanged and the film remained crystal clear. Elongation increased slightly for the first 5 to 7 years of outdoor exposure, probably as a result of stress relaxation. Beyond 10 years, a small decrease was observed. 

C725, a 9 wt % nickel alloy that is further strengthened by 2 wt % tin, is used in electrical connectors and bellows. Properties are summari2ed in Table 21. The alloy has good resistance to stress relaxation at room and moderately elevated temperatures, which accounts for its use in connectors and electrical circuit wire wrap pins. 

Typical properties of these alloys are shown in Table 25. In addition, these alloys exhibit notably excellent resistance to stress relaxation at high appHcation temperatures, for instance 200°C, and in this respect outperform beryUium—copper. However, the electrical conductivity of the strongest Cu—Ni—Sn composition (C729) is lower than that of C172. 

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