Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Technique Annual Technical Progress Report VI January 1 1976 December 31 1976 Summary of Research Activities at Michigan Tech written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of admirality brass stress corrosion in copper sulfate and copper nitrate have provided information on environmental contributions to SCC in acid systems. SCC susceptibility is a function of bulk corrosion rate, and is maximized when conditions favor localized attack. At a given pH and stress, solution composition determines crack initiation rates, but the crack crevice environment is not characteristic of the bulk salt solution. Crack propagation appears to be strongly related to anodic dissolution; however, contributions from thin film rupture and hydrogen embrittlement must be considered. The brittle tarnish rupture mechanism is not operative during the stress corrosion of copper alloys in any of a wide variety of environments. Theoretical models have been developed that are providing a basic understanding of segregation to grain boundaries. The statistical thermodynamic approach using a distribution of energy sites at the grain boundary has extended the McLean model and the results are consistent with sulfur segregation in Ni3Al and Ni3(Al, Ti). A model based on the interatomic potentials of Cu-Cu, Cu-Bi, and Bi-Bi shows the segregation of Bi should occur at grain boundaries and that the segregation should be more extensive at asymmetrical grain boundaries. This is in agreement with earlier measurements made in this program. Grain boundary diffusion experiments continue. The Mo-S-Cr system is still the most desirable one for this purpose but difficulty has been encountered in controlling the sulfur additions and keeping the Cr plate on the surface. A new closed system has been designed that appears to have solved the problem. Experiments using the Cu-Bi-Ni system have been successful so it is clear that the general approach to studying grain boundary diffusion and the effect of impurity segregation on this diffusion will be successful.
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1977 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1980 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Technique Annual Technical Progress Report III January 1 1973 December 31 1973 written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Al/sub 2/O/sub 3/, it was found that additives segregated to grain boundaries. The role of additives on the densification of Al/sub 2/O/sub 3/ and MgO was measured. Segregation of S in Ni, P in W, and Bi in Cu was measured. Work continued on the effect of third element additions for controlling deterioration of properties and on intergranular corrosion in stainless steels. (DLC).
Download or read book A Study of Grain boundary Segregation Using the Auger electron emission Technique Final Report D F Stein L A Heldt written by and published by . This book was released on 1981 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindeks written by and published by . This book was released on 1977 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Technique Annual Technical Progress Report VIII January 1 December 31 1978 written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The susceptibility of nickel-copper alloys to liquid metal embrittlement was studied by Auger spectroscopy. Alloys corresponding to Monel 400 with various levels of additional phosphorous were employed and were given various thermal treatments to control the extent of segregation. Segregation of phosphorous to the boundaries, with accompanying decreases in copper and nickel concentrations, greatly reduces susceptibility to intergranular embrittlement by mercury.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1978 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Technique Annual Technical Progress Report January 1 1979 December 31 1979 written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of grain boundary chemical composition on hydrogen embrittlement was investigated. Auger electron spectroscopy was employed to determine the grain boundary compositions of nickel-copper alloys containing various concentrations of phosphorus and subjected to various thermal treatments. Phosphorus segregates to grain boundaries during slow cooling, accompanied by reduced concentrations of grain boundary copper. Tensile tests were conducted in air and following cathodic charging with hydrogen. All samples tested in air exhibited a completely ductile fracture; ductility was insensitive to grain boundary composition. Fractures of hydrogen-charged samples were brittle and intergranular; elongation to fracture increased significantly with increasing concentration of grain boundary phosphorus. The influence of phosphorus segregation on embrittlement by hydrogen or by mercury (reported previously) is analyzed in terms of additive and interactive mechanisms. A mechanism based on reduced embrittler concentration at the site of bond rupture due to improved atomic packing is proposed and found to be consistent with the experimental results of this and other investigations.
Download or read book A Study of Grain Boundary Segregation Using the Auger Electron Emission Technique written by D. F. STEIN and published by . This book was released on 1972 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Technique Annual Technical Progress Report VII January 1 1977 December 31 1977 written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis of plastic flow at the tip of a propagating crack during brittle fracture has been developed. The plastic flow analysis takes into account the anisotropy of slip by a mixed mode opening scheme. Values of the true fracture energy for different crack systems are obtained; the effects of an embrittling agent can be taken into account. The fracture stresses of Cu--Bi alloys having varied grain sizes and Bi concentrations were measured. Dilute alloys exhibited a decreasing fracture stress with decreasing grain size. Auger analysis indicated a large variation of Bi segregated to boundaries in coarse grained materials with smaller variations in fine grained material. The grain boundary diffusion of nickel was studied in the Cu--Bi alloy system by means of Auger spectroscopy. Bi retards boundary diffusion of Ni; however, the results are quite complex since the Ni presence alters the Bi concentration at the boundary. The Bi concentration tends to decrease to a value approximately equal to that of Ni. Possible effects of solute segregation in determining SCC susceptibility of copper alloys in acid sulfate solution were examined with high purity binary alloys. Grain boundary segregation of Sb and Bi in Cu promoted intergranular SCC in sulfuric acid. Cracking was macroscopically brittle, but significant dissolution occurred along the intergranular crack path. Electrochemical measurements revealed an active path for SCC in segregated Cu--Sb and Cu--Bi alloys. Grain boundary segregation has no effect on the bulk electrochemical properties of unstressed Cu--Sb and Cu--Bi.
Download or read book A STUDY OF GRAIN BOUNDARY SEGREGATION USING THE AUGER ELECTRON EMISSION TECHNIQUE Annual Technical Progress Report written by and published by . This book was released on 1968 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A STUDY OF GRAIN BOUNDARY SEGREGATION USING THE AUGER ELECTRON EMISSION TECHNIQUE Annual Technical Progress Report II written by and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A STUDY OF GRAIN BOUNDARY SEGREGATION USING THE AUGER ELECTRON EMISSION TECHNIQUE Annual Technical Progress Report III written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1982 with total page 1468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Grain Boundary Segregation Using the Auger Electron Emission Techniques Final Technical Report written by and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Grain Boundary Segreation Using the Auger Electron Emission Techniques written by D. F. STEIN and published by . This book was released on 1971 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
