13413 Impact Acoustic Resonance

In several applications of ceramic composites, the damping behavior and the resonant frequency is important. This is especially true for rotating components in turbomachinery. There are primarily two methods that can be used to determine resonant frequency of a component or subcomponent 53, 54 . These are continuous excitation with a swept frequency while monitoring the vibration of the component or by using a sharp impact excitation together with a method to detect the excited vibrations....

13332 Damage from Machining

Machining of ceramic materials is almost always necessary at some point in the manufacture of high-performance structural ceramics. It will not be the purpose of this brief section to review ceramic machining rather the reader is referred to several excellent references on this topic 32-34 . While many methods are under development for machining of ceramics at various stages in the green state, significant machining in the sintered state is still being done. In sintered-state grinding, a...

145 Description Of Various Laserbased Rapid Manufacturing Techniques

All of the laser-based rapid manufacturing processes have the following three common machine elements 1. A laser beam delivery system 2. A powder or wire feedstock delivery system 3. A means to manipulate the laser beam or the part or both in at least three linear dimensions Other enhancements often included in laser-based solid free-form fabrication processes are some type of environmental control apparatus so that processing can be accomplished under an inert or reactive gas environment and a...

793 Carburization Metal Dusting

Besides oxygen attack, high-temperature alloys are frequently subjected to attack by carbon. Gaseous environments generated by many high-temperature industrial processes, particularly in the petrochemical refinery industries, in the conversion of fossil fuels and in certain heat treatment operations, frequently contain gases with carbon activities of up to 1. In other cases, such as in ammonia or methanol synthesis, carbon activities can be much higher than 1. The degradation of metallic...

12282 ISO Standards for Advanced Materials

As shown in Table 12.4 there are a limited number of technical committees specifically dealing with advanced materials, although work on advanced materials may take place within committees dealing with broader topics than just materials. ISO standards can be accessed via the national standards institute of each national member or the ISO Catalogue (either hard-copy form in printed books or in electronic form on compact disk) 14 or through the World Wide Web through ISO's web page 15 . TABLE...

6423 Fatigue Damage Unnotched Specimens

Johnson is considered a pioneer in the field of fatigue damage in uMMCs. From the early days of his Ph.D. thesis in 1979 61 and up to 1988 62 , he suggested that the main cause of fatigue failure in any unidirectional composite system is the damage accommodated by the fiber (failure) and the corresponding loss of stiffness. Experimental observations in alumina-fiber-reinforced aluminum composites, conducted by the U.S. Air Force Materials Laboratory 63 , convinced researchers that the...

References

Lauraitis (Eds.), Fatigue of Filamentary Composite Materials, ASTM STP 636, American Society for Testing and Materials, Philadelphia, 1977. 2. K. N. Lauraitis (Ed.), Fatigue of Fibrous Composite Materials, ASTM STP 723, American Society for Testing and Materials, Philadelphia, 1981. 3. R. Talreja, Fatigue of Composite Materials, Technomic, Lancaster, 1987. 4. P. A. Lagace (Ed.), Composite Material Fatigue and Fracture, 2nd ed. 5 ASTM STP 1012, American Society for...

H32 H34 H36 H38 0 H12 H14 H16 H18

FIGURE 9.1 Effect of cold work on yield strength. FIGURE 9.1 Effect of cold work on yield strength. designation, the two being separated by a hyphen (e.g., 5052-H32). Basic temper designations are letters. Subdivisions of the basic tempers are given by one or more numbers following the letter. F As fabricated. Applies to the products of shaping processes in which no special control over thermal conditions or strain-hardening is employed. For wrought products, there are no mechanical property...

1174 Service and Field Practice

Like the above laboratory-based tests, in-service and field tests are designed to evaluate a range of material degradation processes including erosion-corrosion, stress corrosion, and conventional corrosion processes. In addition information is required concerning material performance within a wide range of operating environments, including atmospheric, sea and fresh waters, high-temperature, in vivo, soils and concrete. In this respect only a brief survey of the relevant test methods can be...