Light alloy

As to inspections performed on light-alloy castings, the expert group agrees on the specifications of marginal conditions that should be met with regard to the required IQI detectability. 

Table 2 System performance for light alloy inspection...

The properties of the imaging system that are needed for inspection, correspond to SC3 for SA and SC2 for SB. The resulting table 2 specifies the requirements placed on the entire system for the inspection of light alloys. 

The sensitivity tests are carried out on artificial defects (nickel-chromium specimens of NFA 09.520,see figure 3 of annex 1) and natural defects (one part in "light" alloy, one part in stellite grade 1 containing micropores, 2 specimens of fracture mechanical type CT20 in Z2 CN 12.10 (NFA 03.180). 

Besides large-diameter pipes, ultrasonic testing is used for checking the welded joints of drill bits, components of wind-driven electric plants, welded joints of light alloys and non-metallic materials, for an integrated inspection of various objects. A range of training aids developed at the Institute allows the operators to be trained effectively. 

Table 10.2 Mechanical properties of structural light alloys...

Leicht-metall, n. light metal (of sp. gr. less than 5 sometimes, specif., an alkali or alkaline-earth metal) light alloy, -dl, n. light oil. leicht-schmelzbar, a. easily fusible, -schmel-zend, -schmelzlich, a. low-melting, -siedend a. low-boiling. 

The aluminium coatings are highly corrosion resistant, and are less liable to contact corrosion than cadmium when in contact with light alloys. They can also be used at temperatures of up to 496°C as against 232°C for cadmium. The aluminium coating is also unaffected by aviation fuels, unlike cadmium. 

The coating is, in addition, useful in preventing galvanic corrosion . Plated on steel which is to be used in contact with aluminium alloys, it protects the steel and does not stimulate the corrosion of the light alloy and is itself not consumed as rapidly as a 100% zinc coating. 

Iridium-192 75 days 0.3, 0.5 3.0 Pipe lines, light alloys, thin sections... 

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