Thermal ageing test

Fio. 35. (a) The concept of complex oxide of zirconia, titania and alumina (AZT) and (b) its effect on thermal durability after thermal aging test at 1,000°C. 

Thermal Exposures. The thermal aging tests on coated and uncoated samples were conducted in Precision forced convection ovens. Temperature uniformity was 1 C, which was determined with a thermocouple array that was mounted in the oven containing a set of dummy samples. No change in temperature uniformity was observed as a result of removing samples periodically for analysis. Test temperatures were 150°C, 110 C, 90°C, 80°C and 70°C for... 

Humidity levels were maintained at <5%, 50%, 70% or 90% +2% RH and a constant temperature of 90°C for a fixed time of 17 days. Samples of historic silk fabric were exposed at 90 °C and 80% RH for either 10 or 30 d. ys to induce further deterioration of mechanical properties. These materials were then coated with 1 and 5 Jim of Parylene-C. Silk samples were loosely affixed by sewing to temperature-resistant coarse polyester mesh which allowed both free air flow and also avoided contact between the metal and the fabric surfaces during the thermal aging tests. 

A thermal ageing test shows that the x of 3RDCVXY is stable even when kept at 80 C for more than 6 months. The thermal and temporal stability make 3RDCVXY a viable substitnte for the cnrrent inorganic electro-optical (EO) materials. The stability of these... 

Figure 11. Thermal aging tests at 120°C for the aramid elastomer samples (a) TPARl ( ) TPAR2 ( ) TPAR3 [42]...

Fig. 6.8 Schematic illustration of Ciofer22APU plate/SACN sealant/ASC joined SRU subjected to dual atmosphere thermal ageing test (Smeacetto and coworkers 2011)...

Specimens used in tests were sections of cables with PVC outer coating. PVC was plasticized with DOF softener. The materials considered were exposed to the radiation and thermal aging. The samples have been irradiated at room temperature by hard gamma rays with 10 rad/sec dose power. A number of samples had been heated for long different times at 90°C. Besides a special specimens were cut out from outer coating for test on tensile machine like "Instron". The total doses of irradiation, times of heating and elongations at break obtained with "Instron" are listed in Table 1. 

Elevated drum Evaluate thermal stability parameters of material temperatures (isothermal aging tests, SADT, etc.) reaching Self, Keep drums away from source of heat Accelerating Decomposition store at required temperature Temperature (SADT). CCPS G-15 CCPS G-22 CCPS G-29 CCPS G-30... 

Insulation systems were first classified according to the material used, and permissible temperatures were established based on the thermal aging characteristics of these materials. For example. Class B insulation was defined as inorganic materials such as mica and glass with organic binders 130°C was the allowable maximum operating temperature. The present definition of insulation system Class B stipulates that the system be proven. . by experience or accepted tests. .. to have adequate life expectancy at its rated temperature, such life expectancy to equal or... 

Ogawa et al. [100,101] reported the use of various EPDM polymers in blends with NR in black sidewall formulations. Laboratory testing showed improved resistance to crack growth and thermal aging. 

Firing experiments induced thermal transformations on the ochre-precipitates. From these experiments, hematite and a well crystalline arsenate resulted. This indicates that arsenic may be scavenged by an arsenic-rich compound, freshly formed during the initial stages of the water treatment. This is in agreement with the results obtained by Jia Demopoulos (2008), when performing aging tests on solids precipitated from As(V)-Fe(lll) solutions. 

Experience has also shown that in cases such as stress rupture and thermal ageing the test parameters may have to be designed progressively. Shorter tests at higher loads (or temperatures) are set up first and the times to failure measured. The test conditions for longer lifetimes are then set on the basis of these results. This is particularly important where the validity of the final result depends on obtaining a failure within a particular time interval, e.g., over 5,000 h as in IEC 60216 [2], or where the measurements must be completed within a set time. 

I have lost no sleep in debating what is physical - if popular opinion treats tests as part of the physical spectrum (e.g. ageing tests) then they are physical. Not surprisingly, chemical analysis is excluded but it can be noted that the thermal analysis techniques straddle both camps and they have been included or excluded depending on their purpose. The intention has been to include every type of physical test and, hopefully, this has been, in the main, achieved. However, three areas immediately come to mind which do not have their own section, acoustic properties, optical properties and nondestructive testing. 

Thermal ageing is a principle factor in the lifetime of rubbers which is critically important for virtually all products. Consequently, there is a vast amount of literature on how estimates of service life can be obtained from heat ageing tests... 

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