basic asnt review 3rd Flashcards
fracture is the type of material failure. of the following, which is another type of material failure? (fracture mechanics, low frequency dynamic loading, Permanent deformation, elongation within the Elastic range)
Permanent deformation
which of the following statements best differentiates between a defect and a discontinuity (all discontinuities are defects, all defects will lead to failure if detected, discontinuities can propagate and become defects, discontinuities are external natural boundaries only; Defects are internal flaws )
Discontinuities can propagate and become defects
Nondestructive testing is often differentiated from other measurement Or inspection technique In that
Nondestructive testing involves indirect tests related to some other quality or characteristic of the material
Which of the following describes a function of nondestructive testing (identification and sorting of material, identification of material properties, assuring absence of faults or defects that could cause a part to fail)
All of these
An important basis for the success of fracture control design procedures is
The need to assure that unexpected flaws of some critical size are not present when the component enters service
properly used, nondestructive testing can assist in fracture control by
Providing an accurate evaluation of the number and type of discontinuities that exist in the material
a statement that a particular experiment to produce to .9 probability of detection with a 95% of Confidence level means that
There is a 5% probability that the probability of detection is overstated
The most solid metals and plastics that have reasonable strength at room temperature are called
Allotropic materials
Material properties as used in design, are most frequently determined by
Material testing
Even at the early stages of product planning, nondestructive testing should be considered because (may be required by codes and specifications, the design of the part should permit easy access to critical areas for inspection, the materials selected should be compatible with an nondestructive technique that can accurately evaluate the product)
All of these
Which of the following material properties are of most concern if corrosion resistance is essential (Processing Properties, mechanical properties, physical properties, Chemical Properties )
Chemical Properties
Which of the following is true relative to the comparison of the properties of aluminum based alloys and iron base of alloys (iron has a lower melting point than aluminum, iron can exist in different crystalline structures and it can be controlled by heat treatment, iron can be alloyed to increase its strength whereas aluminum is strongest in its pure state, iron is preferred in load carrying designs but should not be used in any deformation type of manufacturing process)
iron can exist in different Crystalline structures, and its properties can be controlled by heat treatment
Tensile tests are conducted on specimens from a newly developed alloy in order to determine the ultimate Tensile strength of that material. Such tests are called
Destructive tests
A bar that is 12 inches long, 2 inches wide, and 1 inch thick is subjected to a Tensile load acting along the length of the bar of 36,000 pounds. What is the tensile stress within the bar
18,000 PSI
The modulus of elasticity, or Young’s modulus, is related to the materials relative
Stiffness or yield strength
Which of the following materials is typically considered when the application only requires High compressed of strength (Low carbon steel, high carbon steel, cast iron, magnesium )
Cast iron
A fatigue failure can often be prevented by using non destructive testing to
Detect surface discontinuities that could be stress risers
Which of the following tests uses a pendulum to break a specimen that is notched and supported on both ends, with the result of measuring energy absorption (creep test, charpy test, fatigue test, transverse rupture test)
Charpy test
Direct hardness tests provide a measure of a materials ability to resist
Surface and near surface penetration
A particular type of steel has an ultimate strength of 80,000 pounds psi, an elastic limit of 60,000 PSI and a yield strength of 62,000 PSI. An allowable design stress of 20,000 PSI is used, what is the factor of safety based on the ultimate strength
Four
Under ordinary usage, metals exist as
Crystalline solids
The terms of body centered cubic, face centered cubic, and hexagonal close packed all refer to the
Lattice structures that make up unit cells in a solid metallic Structure
the process of returning ductility to a cold work low carbon steel is called
Recrystallization
Many metals exhibit an increase in strength caused by plastic flow beyond elastic limit. This effect is called
Work hardening