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ASNT Level 3 Basic Materials & Processes
Fracture is a type of material failure. Of the following which is another type of material failure? - Permanent deformation. Which of the following statements best differentiates between a defect and a discontinuity?
- Discontinuities can propagate and become defects. Nondestructive testing is often differentiated from other measurements or inspection techniques in that: - NDT involves indirect tests related to some other quality or characteristic of material. What are the functions of NDT? - Identifying and sorting of material. Identifying of material properties. Ensuring absence of faults or defects that could cause a part to fail. An important basis for the success of fracture control design procedures is: - The need to ensure that unexpected flaws of some critical size are not present when the component enters service. If properly used, NDT can assist in fracture control by: - Providing an accurate evaluation of the number and type of discontinuities that exist in a material. A statement that a particular experiment produced a 0.9 probability of detection with a 95% confidence level means that: - There is a 5% probability that the probability of detection is overstated. Most solid metals and plastics that have reasonable strength at room temperature are called: - Engineering materials. Material properties, as used in design, are most frequently determined by: - Materials testing. Even at the early stages of product planning, NDT should be considered because: - The design of the part should permit easy access to critical areas for later inspection. which of the following material properties are of most concern if corrosion resistance is essential? - Chemical properties. Which of the following is true relative to the comparison of the properties of aluminum- based alloys and iron-based alloys? - Iron can exist in several different crystalline structures and its properties can be controlled by heat treatment.
Tensile test are conducted on specimens from a newly developed alloy in order to determine the ultimate tensile strength of the material. Such tests are referred to as: - Destructive tests. A bar that is 2 in. long, 2 in. wide and 1 in. thick is subjected to a tensile load acting along the lenght of the bar of 36000 lbs. What is the tensle stress within the bar? - 18000 psi. What is Point B on the Stress-Strain diagram where it first starts to curve? - Elastic limit. Stress-Strain diagram, which of the following ranges indicates the affect of work hardening, to its maximum, caused by plastic flow of the material during a tensile load? - Deformation rate to the ultimate strength On the Stress-Strain diagram, the points represented by E and F would be closer together if the material being tested were: - Less ductile. The modules of elasticity, or Young's modules, is related to the material's relative: - Stiffness and yield strength. Which of the following materials is typically considered when the application only requires high compressive strength? - Cast iron. A fatigue failure can often be prevented by using NDT 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 results of measuring energy absorption? - Charpy test. What is a S-N curve? - An endurance limit curve diagram. Direct hardness test provide a measure of a material's ability to resist: - Surface and near- surface penetration. Under ordinary usage, metals exist as: - Crystalline solids. The term body-centered cubic BCC, face-centered cubic FCC and hexagonal close-packed HCP all refer to the: - Lattice structures that make up unit cells in a solid metallic structure. The process of returning ductility to cold-worked low-carbon steel is called: - Recrystallization. Many metals exhibit an increase in strength caused by plastic flow beyond the elastic limit. This effect is called: - Work hardening. When used as in-process treatment, Re crystallization can: - Improve ductility.
Corrosion resistant steels having relatively high percentages of nickel and chromium are called - Stainless steel Low carbon steel contains approximately: - 0.06 to 0.25% carbon Austenitic stainless steels are paramagnetic; this means that: - The material has a very low permeability. Which of the followingis an advantage of cast steel over wrought steels? - Cast steels have more isotropic properties than wrought steel. Which of the following nonferrous metals is the most important structural material? - Aluminum alloys Which of the following statements is true regarding the electrical conductivity of aluminum alloys? - Conductivity decreases at elevated temperatures. The heat treatment of aluminum for the purpose of hardening and strengthening: - Can produce tensile strengths equivalent to some carbon steels. Which of the following metals has low strength, high corrosion resistance and is used largely in die casting operations? - Zinc. Which of the following metals alloys has a density approximately two-thirds that of aluminum? - Magnesium. Brass and bronze are alloys of zinc, tin and a large percentage of: - Copper. Monel and inconel are: - Nickel alloys. Which of the following materials cannot typically be used in the as-cast state? - Carbon A high-strength, low density corrosion resistant metal alloy of significance in the aircraft, marine and chemical processing industries is: - Titanium. Which of the following statements is true concerning plastics following their initial polymerization. - Thermosetting plastics do not soften, but char and deteriorate when reheated. Based on the strength to weight ratio: - Some plastics, including nylon, may have strengths greater than some metals. Design engineers are responsible for establishing the function, appearance, quality and cost of a product. Regarding the role of NDT in product design, which of the following is true? -
Designer should seek input from NDT personnel to insure all required inspections can be performed. Manufacturing is a term that refers to processing that starts with raw material in bulk form and is concerned mainly with processing the raw material in a manner that changes its: - Shape. Manufacturing process changes raw material by: - Machining. Which of the following is true regarding solidification of molten metal in a casting mold? - Cooling takes place in phases having different rates that produced different types of grain structures in different sections of the casting. In casting, shrinkage occurs: - Before, during and after the transformation from liquid to solid Large voids or porosity in a casting result from: - Gas evolution before and during solidification. During the solidification of a casting, the shrinkage that occurs: - May cause cavities that are enlarged by the evolution of gases. The design of the casting is important because the quality of the finished product can be adversely affected by all of the following except: - Temperature of the mold immediately prior to casting. The design of the casting is important because the quality of the finished product can be adversely affected by all of the following. - 1. Lack of molten metal to compensate for contraction.
- Location of gate with reference to either progressive solidification or directional solidification.
- The location of hot spots in ares of the casting that are isolated by thin sections. The term used to describe a discontinuity in a casting that occurs when molten metal interfaces with already solidified metal with failure to fuse at the interface is: - Cold shut. The part of the casting where the gate or riser was attached: - May provide a concentration point for discontinuities. Risers, feeders, or feed heads in casting serve to provide sources of molten metal to compensate for: - Shrinkage. Green sand casting molds include: - Sand, clay and water. Mold material in the form of inserts that exclude metal flow and thus form internal surfaces or passages in a casting are called: - Cores.
Soldering, brazing and braze welding all - Use a process where only the filler metal is actually melted Due to high temperatures and rapid rate of cooling, the filler material used in fusion welds - Contains alloys that will help compensate for properties lost during the welding process The uneven shrinkage and brittle structures that occur due the rapid cooling of a weld can often be reduced by - Preheating the weldment prior to welding After welding, many steel weldments are heat treated to obtain more uniform properties between the weld and base metal and to relieve stress. Which heat-treatment method is often used following welding - Normalizing Weldments subject to restrain during welding can develop high residual stress. Unrestrained weldments can develop - Geometric distortion Welds and weldments have been known to develop cracks long after cooling but prior to being used in service. What is the principal cause for such cracks - Excessive residual stresses In arc welding the electric arc is usually sustained between an electrode and the - Workpiece. Which of the following gases are most frequently used as shielding to provide an inert atmosphere in the vicinity of the weld - Argon, helium and carbon dioxide. When molten metal is transferred from the electrode to the weld zone, it can be shielded from the atmosphere by all of the following - The burning of coatings on the welding electrode. Maintaining the arc beneath flux powders. The flow of a shielding gas around the arc. The burn-off rate and amount of spattering during the arc welding process can often be controlled by - Selecting the proper electrode polarity Which of the following welding process uses a nonconsumble electrode with the arc maintained in a atmosphere of inert gas - Gas tungsten arc welding Shielding in the submerged arc welding process is provided by - Granular flux that completely surrounds the arc. A welding process that is most frequently carried out in a vacuum chamber is - Electron- beam welding The welding process capable of very high intensity and rate of heat transfer is - Plasma arc welding
The welding process in which the arc is extinguished after melting a slag cover and in which the base metal and copper slides form a sort of moving mold is called - Electroslag welding In the process of diffusion welding, often called diffusion bonding, the base metal is joined by - Putting it under pressure at temperatures below the melting point A slag inclusion can result from which of the following - Insufficient cleaning of successive passes in a multipass weldment. Undercut on a weld pass is usually caused by - Poor operator technique. Crater cracks may take the form of a single crack or star-shaped cracks and will usually be found - Anywhere along the weld where the welding was stopped and restarted. The principal purpose of preheat treatment and post-heat treatment in welds is to - Neutralize residual stresses and geometric distortion. In welding the most obvious defects are those associated with structural discontinuities in the weld itself. Conditions not considered welding process defects are - Corrosion of the structural members Cracks in the weld metal are primarily of which three types - Longitudinal, transverse and crater. Thermal conductivity of a metal is an important factor to consider in making quality weldments because - Some metals, such as stainless steel, have low conductivity, which results in weld defects caused by localized overheating. Deformation of metals provides a number of advantages. Which of the following is an advantage - High duplication accuracy results from most deformation processes. In general, the properties of wrought metals are improved over their cast counterparts. Thin sections can be more economically and more successfully produced than by casting. Among other things, the advantageous effects of recrystallization depend upon the - Temperature at which deformation takes place. Wrought products invariably exhibit - Directional properties. During the steel-making process, a large number of faults such as slag, porosity and shrinkage cavities exit in the top of the ingot. These discontinuities are - Removed by cropping up to one-third off the top of the ingot.
Powder metallurgy provides two unique advantages in metal processing. One is the capability to produce shapes and objects of refractory metals that are extremely difficult or impractical to melt; the other is to - Produce metal shapes with controlled porosity A major purpose of pressing the metal powders during powder metallurgy processing is to
- Compact the powders into mechanical and atomic closeness In the powder metallurgy process, sintering is - In most cases, a fully solid state process Powdered metallurgy products cannot - Attain 100% of theoretical density Which of the following is an application for powdered metal products - Cemented carbide cutting tools and dies. Tungsten rocket nozzles. Oil-impregnated bushings. Which of the following terms describe operations that bend, stretch and shape ,metals into three dimensional shapes with significant plastic flow and deformation - Bending. Forming. Drawing. In drawing and deep drawing, the final shape often can be completed in a series of draws, each successively deeper. What process performed between draws might effectively reduce the number of draws required - Recrystallization. Spinning can be used to form - Spherical tank halves Most new developments in sheet metal forming typically use nonconventional energy sources. What is a common feature of these processes? - The use of energy sources that release large amounts of energy in a very short time. Machines designed to hold a cutting tool and a workpiece and establish a suitable set of motions between them to remove material from the workpiece are called - Machine tools In describing machinability, three different measurements are generally considered on a relative, if not quantitative, basis. These are - Surface finish of the material achievable, power consumption required to remove a given volume of material and expected tool life When used with respect to machine tools, the acronym N/C means - Numerical control Which of the following can result in economical setup and reduced machine time with an increase in repeatability and accuracy for variety of machining operations - The use of numerical control systems applied to conventional types of machining operations
Which of the following statements is true regarding plastics processing - Both thermoplastics and thermosetting plastics may be processed by molding, casting and extrusion Reinforced plastics molding involves use of - Thermosetting plastics and fibrous reinforcement materials The mechanism of adhesion combines mechanical interlocking and - Interatomic forces Which of the following statements is true concerning composite materials - Composite materials can be wrapped over metallic materials to increase strength and reduce weight Which of the following statements is true concerning honeycomb - Nonmetallic honeycomb derives high strength and rigidity from a structural combination of relatively weak, thin, lightweight materials The major difference between materials classified as composites and those classified as mixtures is that - Mixtures are a type of composites with random orientation and shape of the constituents. The acronym EDM refers to - Electrical discharge machining The process used for shaping metals be chemical dissolution only, with selective removal accomplished by masking areas where metal is not to be removed, is called - Chemical milling A process that is the reverse of electrochemical machining and that is the basis for electroplating is called - Electroforming A cutting operation that has the ability to cut through thickness of over 0.9 m 3 ft of steel and is commonly used to remove surface defects on castings and forgings by scarfing is called - Oxyacetylene cutting. Which of the following statements is true concerning surface finishing - Cleaning operations are considered to be surface-finishing process. Surface finishing is often performed for corrosion protection. Surface finishing is sometimes performed to improve surface and near surface mechanical properties Carburizing and flame hardening are examples of - Case hardening process Which of the following nondestructive tests would provide the best results in measuring the case depth on a case hardened part. - Eddy current Coatings are often applied to protect a material; their thicknesses can frequently be determined nondestructively by - Eddy current
Gages such as plug gages, ring gages, go/no-go gages, profile gages, thread gages, radius gages, ect., are all types of - Fixed gages Devices that show magnified reflected of profile images of the workpiece on a frosted glass screen are called optical - Comparators
