The Materials Science of Coatings and Substrates Part 7 pptx

... deterioration of their properties. The rate of the phenomenon depends largely on the nature of the metals, the attacking gases, and the new products that may form at the interface between the two ... unstable and converts to a phase with the release of hydrogen and causes a contraction of the lattice and cracking of the deposit. Deposits with...

Ngày tải lên: 10/08/2014, 12:21

... composition of products and expanded use of computers in modeling behavior of materials. According to the report: " ;The field of materials science and engineering is entering a period of unprecedented ... 11. Materials Science and Engineering for the 1990's-Maintaining Competitiveness in the Age of Materials, By the Committee on Materials...

Ngày tải lên: 10/08/2014, 12:21

... of hydrogen absorbed are the composition and metallurgical structure of the alloy, the composition and temperature of the etching solution, the etching time, the sequence in which the ... is greater than that of the rod but less than that of the rod and the coating. The bond strength can be calculated by using the load to cause failure and the...

Ngày tải lên: 10/08/2014, 12:21

... 70 75 aluminum sample after testing. The failure in the aluminum is clearly evident; no damage is seen in the nickel plating or at the interface bclween the nickel and the aluminum. Often ... clearly show the importance of the mechanical roughening (sandblasting) part of the process. Without the mechanical roughening step, the subse- quent anodic etch wa...

Ngày tải lên: 10/08/2014, 12:21

... indicator of ductility is measurement of the reduction of area of the sample rather than elongation ( 17) . Reduction of area is largely a measure of the inherent ultimate ductility of a material ... 80 70 0 15 77 100 10.9 90.8 20 76 800 12.1 93.9 29 39 600 74 70 0 12.6 94.4 54 38 70 0 70 900 91 33 200 71 000 31 .8 90 .I3 144 37 600 70 900 29....

Ngày tải lên: 10/08/2014, 12:21

... texture and fractals. STRUCTURE OF ELECTRODEPOSITED AND ELECTROLESS COATINGS The properties of all materials are determined by their structure. Even minor structural differences often have profound ... Epitaxy is the orderly relation between the atomic lattices of substrate and deposit at the interface, and is possible if the atomic arrangement in a certain cr...

Ngày tải lên: 10/08/2014, 12:21

... a much better understanding of the science governing the mechanisms and functions of additives for plating solutions, much of the work has been of the "trial and error" or Edisonian ... a set of "boxes" of side length b, and a count is made of the non-empty boxes N shown in Figure 36, Then the box size is changed and the co...

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... susceptibility to the effect of additives, and the order of this susceptibility is roughly the same as the order of their melting points, hardness and strength; it increases in the order Pb, ... 224 125 106 55 79 Recess 94 72 53 63 80 1 63 212 65 64 55 57 Foil A Bottom eaiak Recess 42 27 33 33 76 53 47 81 177 91 163 160 94...

Ngày tải lên: 10/08/2014, 12:21

... thicker plates ( 27) . The direction of the change as a function of thiclaiess depends on the microthrowing power of the solution, and is therefore, specific to the type of solution used ... varies with: 1) the concentration of all salts in the solution; 2) the presence of addition agents; 3) the accumulation of aging byproducts; 4) the form of...

Ngày tải lên: 10/08/2014, 12:21

... this often occurs in the initial stages of deposition, it can only remain throughout the coating when the atomic parameters of the deposit and the substrate are approximately the same. ... of stress and has been used in the electroforming of optical components (33). Plating is done on a strain gage simultaneously with the part (Figure 11). As the p...

Ngày tải lên: 10/08/2014, 12:21