Midterm Exam of AERAS Kenoal 1. First Principle of Fallure Analysis is: a) Polishing surface c) Macroscopic examination b) Observing without touching Times 30 min 2. Which one is not a fallure analysis tool? d) Microscopic examination a) Transmission electron microscopy c) Inductively Coupled Plasma (ICP) analysis b) Optical microscopy d) Scanning electron microscopy 3. Chromatic and spherical aberration in optical microscopy are known as: a) Resolution modifier b) Contrast maker c) Light scatterer d) Lens errors 4. Which conditions are typically represented in a phase diagram? a) Pressure, volume, and atomic weight b) Temperature and time c) Temperature, pressure, or chemical composition d) Pressure and volume 5. What type of failure can result from improper maintenance or repair? a) Cavitation b) Chemical attack c) Welding d) Stress corrosion 6. What causes disintegration at elevated temperatures? a) Sonic vibrations b) Thermal shock c) Attack by liquid metals or platings d) Severe vibration 7. Which option is the most common cause of failure in aircraft parts? a) Stress corrosion b) Fatigue c) High-temperature oxidation d) Overload . Which of the following is NOT explicitly mentioned as a step in failure analysis? a) Description of the failure situation b) Visual examination c) Testing for radiation damage d) Chemical design analysis Metallographic sections are typically taken through which areas? b) Fracture surfaces and other locatior a) Contaminated regions only c) Clean and polished surfaces d) Areas with the most corrosion Wall 2024

1. The correct answer is b) Observing without touching. The First Principle of Failure Analysis is to observe the failure without touching the component to avoid contamination or altering the failure mechanism.<br /><br />2. The correct answer is c) Inductively Coupled Plasma (ICP) analysis. ICP analysis is not a failure analysis tool. Failure analysis tools typically include microscopic examinations (a, b, d) and various testing methods to analyze the material and component properties.<br /><br />3. The correct answer is d) Lens errors. Chromatic and spherical aberration in optical microscopy are types of lens errors that affect image quality and clarity.<br /><br />4. The correct answer is c) Temperature, pressure, or chemical composition. A phase diagram typically represents the conditions of temperature, pressure, and chemical composition at which different phases of a material exist.<br /><br />5. The correct answer is d) Stress corrosion. Improper maintenance or repair can lead to stress corrosion, a type of corrosion that occurs when a material is subjected to mechanical stress and exposure to a corrosive environment.<br /><br />6. The correct answer is b) Thermal shock. Disintegration at elevated temperatures can be caused by thermal shock, which occurs when a material is exposed to sudden and severe temperature changes.<br /><br />7. The correct answer is b) Fatigue. Fatigue is the most common cause of failure in aircraft parts due to repeated loading and unloading cycles that can lead to material failure over time.<br /><br />8. The correct answer is d) Chemical design analysis. Chemical design analysis is not explicitly mentioned as a step in failure analysis. The steps typically involve describing the failure situation, conducting visual examinations, and testing for various factors such as radiation damage.<br /><br />9. The correct answer is b) Fracture surfaces and other locations. Metallographic sections are typically taken through fracture surfaces and other relevant areas of interest to analyze the failure mechanism and gather information about the material's microstructure and properties.