Mines Repository (Colorado School of Mines)
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Summerfield tungsten property, Mineral County, Nevada
No full textMine report no. 1795.Includes maps.Typescript (carbon copy).Title supplied by cataloger.Report on property of the Summerfield Tungsten Company / E.W. Bedford -- Report on Summerfield Tungsten mine / Oscar H. Hershey -- Reconnaissance report on the Summerfield (Gunmetal) tungsten mining property near Mina, Nevada / George E. Collins
Bassick mine
No full textMine report no. 2115.Includes illustrations and maps.Title assigned by cataloger.Report on the Bassick Mine / Henry Cummins -- Bassick Mining Company stock certificate -- Prospectus of the Bassick Contact Gold and Silver Mining and Milling Co. of Custer County, Colorado -- Geognostic map of the Bassick contact fissure of Custer County, Colorado / Carl Wulsten
Report on the McCarthy graphite deposit near Lusk, Wyoming
No full textMine report no. 1963.Typescript (carbon copy).Includes assay certificate, 2 maps, and 3 photograph negatives
Lithography-free mesa isolation of multijunction III-V solar cells through laser ablation
No full textIncludes bibliographical references.2025 Spring.Eliminating photolithography from solar cell processing is a significant opportunity for cost reduction for III-V solar cells. In this work, we test femtosecond laser ablation and scribing as an alternative to contact photolithography and wet chemical etching for mesa isolation, when processing multijunction cells. We demonstrate that upright multijunction solar cells isolated by using the laser as a scribe to cleave through the substrate had virtually no performance loss when compared to a baseline cell processed with photolithography. By contrast, cells isolated by laser ablating through the active layers have performance losses that cannot be fully eliminated with post-processing etches. So far no laser mesa isolation methods have been viable for producing inverted solar cells with good performance characteristics, though further exploration into this subject is being made. This demonstration of photolithography-free mesa isolation with no performance losses is promising for less expensive III-V manufacturing
Hydrogen embrittlement of high strength steels for fastener applications
No full textIncludes bibliographical references.2025 Spring.High-strength steel fasteners can be susceptible to hydrogen embrittlement when hydrogen is introduced cathodically during processing or in service conditions, leading to unexpected, brittle failure. Microalloying to precipitate fine alloy carbides can be used to trap hydrogen and mitigate hydrogen accumulation at susceptible microstructural features and stress concentrators. However, increasing trap density increases the driving force for hydrogen absorption during cathodic or gaseous hydrogen charging in microalloyed conditions compared to non microalloyed conditions of similar strength. In this study, the effects of V and Mo microalloying and alloy carbide precipitation on hydrogen embrittlement susceptibility are investigated for a range of cathodic hydrogen pre charging and in situ charging conditions to determine whether the increase in trapping capacity can increase resistance to hydrogen embrittlement despite increased hydrogen absorption. Additionally, hydrogen embrittlement is evaluated in notched and smooth specimens with continuous displacement and notched specimens with static loading to study the differences between hydrogen embrittlement behavior with different hydrogen embrittlement evaluation methods. Melt extraction and thermal desorption analysis were used to characterize the hydrogen concentration with different alloying, heat treatment, and charging parameters. For the same strength level, V microalloyed conditions were found to increase the resistance to embrittlement across a range of temperatures up to a point near saturation despite increased hydrogen absorption compared to a V-free condition. When tempered to the same strength level, the addition of Mo to the V-added condition further increased the resistance to hydrogen embrittlement with similar hydrogen absorption behavior. Alloy carbides are interpreted to increase resistance to hydrogen accumulation at stress concentrators by reducing hydrogen diffusion and trapping a portion of diffusible hydrogen. Notched specimens were sensitive to hydrogen accumulation at the notch, with embrittlement detected in conditions with little hydrogen charging. Smooth specimens were less sensitive to hydrogen charging without coordinated diffusion toward a large stress concentrator such as a notch during loading, and hydrogen accumulation and fracture were observed at several local stress concentrators assumed to be inclusions in the gauge section. Constant load testing led to fracture at lower stress compared to continuous displacement, and the difference between the two testing methods was larger between conditions with less total hydrogen. Conditions with high total hydrogen concentration are less time sensitive because hydrogen can quickly accumulate to critical concentrations when a stress concentrator is introduced
Notes on the Marshall Lake district, Idaho County, Idaho
No full textMine report no. 1729.Typescript (carbon copy)
Keystone mine, Coahuila, Mexico
No full textMine report no. 2036.Typescript (carbon copy).Title supplied by cataloger.One report is not dated.The Key Stone mine / J.H. Collard -- Report on the Keystone mine / Andre Formis
Report on the San Felix, San Pedro, and others, Altar district, Sonora, Mexico
No full textMine report no. 2061.Includes two maps.Typescript (carbon copy)
Wide Awake mine, Colusa County, California
No full textMine report no. 2004.Typescript (copy).Title supplied by cataloger.Includes maps and two versions of the Reade report
