WorldWideScience

Sample records for allisions

  1. A comparative wear study on Al-Li and Al-Li/SiC composite

    Energy Technology Data Exchange (ETDEWEB)

    Okumus, S. Cem, E-mail: cokumus@sakarya.edu.tr; Karslioglu, Ramazan, E-mail: cokumus@sakarya.edu.tr; Akbulut, Hatem, E-mail: cokumus@sakarya.edu.tr [Sakarya University Engineering Faculty, Department of Metallurgical and Materials Engineering, Esentepe Campus, 54187, Sakarya (Turkey)

    2013-12-16

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al{sub 2}O{sub 3} ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms{sup −1} and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  2. Sample preparation technique for transmission electron microscopy anodized Al-Li-SiC metal matrix composite

    International Nuclear Information System (INIS)

    Shahid, M.; Thomson, G.E.

    1997-01-01

    Along with improved mechanical properties, metal matrix composites (MMC) have a disadvantage of enhanced corrosion susceptibility in aggressive environments. Recent studies on corrosion behaviour of an Al-alloy 8090/SiC MMC, revealed considerably high corrosion rates of the MMC in near neutral solutions containing chloride ions. Anodizing is one of the potential surface treatment for the MMC to provide protective coating against corrosion. The surface and cross section of the anodized MMC can easily be observed using scanning electron microscope. The anodizing behaviour of the MMC can be understood further if the anodized cross section in examined under transmission electron microscope (TEM). However, it is relatively difficult to prepare small (3 mm diameter) electron transparent specimens of the MMC supporting an anodic film. In the present study a technique has been developed for preparing thin electron transparent specimens of the anodized MMC. This technique employed conventional ion beam thinning process but the preparation of small discs was a problem. A MMMC consisting of Al-alloy 8090 with 20 % (by weight) SiC particulate with an average size of 5 Mu m, was anodized and observed in TEM after preparing the samples using the above mentioned techniques. (author)

  3. 77 FR 69564 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Science.gov (United States)

    2012-11-20

    ... schedule that governs the Burlington Northern Santa Fe (BNSF) Railway Company swing span bridge across... schedule of the swing span railroad bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... scheduled repairs necessitated by a bridge allision. This deviation allows the bridge to remain in the...

  4. 77 FR 27115 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Science.gov (United States)

    2012-05-09

    ... schedule that governs the Burlington Northern Santa Fe (BNSF) Railway Company swing span bridge across... swing span railroad bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana. The... scheduled repairs necessitated by a bridge allision. This [[Page 27116

  5. 77 FR 42637 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Science.gov (United States)

    2012-07-20

    ... schedule that governs the Burlington Northern Santa Fe (BNSF) Railway Company swing span bridge across... schedule of the swing span railroad bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... to complete scheduled repairs necessitated by a bridge allision. This deviation allows the bridge to...

  6. 77 FR 46286 - Drawbridge Operation Regulation; Bayou Boeuf, Amelia, LA

    Science.gov (United States)

    2012-08-03

    ... (BNSF) Railway Company swing span bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish... the swing span railroad bridge across Bayou Boeuf, mile 10.2, at Amelia, St. Mary Parish, Louisiana... equipment. The deviation is necessary to complete scheduled repairs necessitated by a bridge allision. This...

  7. 75 FR 19880 - Safety Zone; BW PIONEER at Walker Ridge 249, Outer Continental Shelf FPSO, Gulf of Mexico

    Science.gov (United States)

    2010-04-16

    ... BW PIONEER, a Floating Production, Storage and Offloading (FPSO) system, at Walker Ridge 249 in the Outer Continental Shelf. The purpose of the safety zone is to protect the FPSO from vessels operating... reduces the threat of allisions, oil spills, and releases of natural gas, and thereby protects the safety...