Diffusion welding Clause Samples

Diffusion welding. Diffusion welding makes use of the principle of solid-state diffusion. Atoms of two solid, metallic surfaces intersperse themselves over time. In addition, the welding process depends on the applied pressure and the process temperature. In figure 18 the design of a press for diffusion welding is shown which is used due to the expected high stress for the material. The press consists of two halves of aluminium, four screws and four guidance pins for the absorber foils. The lower part of the press fits to the intake of the holder in the micro dispensing system. Glass slides, borosilicate glass with dimensions of 0.2 mm × 18 mm × 18 mm, are used as separating layers during the diffusion process. Otherwise, the gold would also be welded to the press itself. For the actual diffusion welding process, the loaded press is placed in an oven, and exposed to a well-defined temperature for a fixed time. The absorber array with the radioactive material is mounted on a glass aluminium assembly and a second absorber array of the same shape and thickness but without radioactive material is placed on top of it. With the help of the guidance pins the absorber foils cannot shift against each other. The other glass aluminium assembly is put on-top of the absorber-source-absorber sandwich, and the four screws are fastened to produce a pressure. Then, the guidance pins are removed otherwise the gold could also be welded to the pins. Depending on the deposited radioactive material and the used carrier solution, suitable parameters of diffusion welding can differ significantly. To avoid melting or outgassing of the radioactive material, the parameters were adjusted. Several tests were done to identify suitable diffusion welding process parameters. For materials with high melting points of all chemical compounds, e. g. 36Cl, the following parameters were determined: Torque 2 Nm per screw Oven temperature 400°C Process time 45 min to reach 400°C and 1 hour at 400°C Cooldown 12 hours For materials with low melting points of one chemical compound, e. g. 99Tc and 14C, the following parameters were determined: Torque 10 Nm per screw Oven temperature 140°C Process time 45 min to reach 140°C and 40 h at 140°C Cooldown 12 hours After diffusion welding, the press is carefully opened because there might be broken glass slides, seen in figure 19. The broken glass is removed from the welded gold foils and collected for further tests. In case of a successful diffusion welding, the radioactive ...
View Source

Related to Diffusion welding

  • Welding Welding and use of cutting torches or cutoff saws will be permitted only in areas that have been cleared or are free of all material capable of carrying fire. Flammable debris and vegetation must be removed from within a minimum 10-foot radius of all welding and cutting operations. A shovel and a 5-gallon standard backpack water container filled and with handpump attached shall be immediately available for use in the event of a fire start. C8.64 – DEBARMENT AND SUSPENSION CERTIFICATION (3/18). Pursuant to 2 CFR 180 and 2 CFR 417, Purchaser shall certify and obtain certifications from its Subcontractors regarding debarment, suspension, ineligibility, and voluntary exclusion, including additional Subcontractors obtained after award of this contract. “Subcontractors” are participants in lower tier covered transactions. Purchaser may rely upon a certification of a prospective Subcontractor that it is not proposed for debarment under 48 CFR 9.4, debarred, suspended, ineligible, or voluntarily excluded from participating in covered transactions or timber sales, unless Purchaser knows that the certification is erroneous. Purchaser shall keep the certifications of its Subcontractors on file until timber sale Termination Date and any extensions thereof, and will provide a copy at the written request of Contracting Officer. Nothing contained in the foregoing shall be construed to require establishment of a system of records in order to render in good faith the certification required by this Subsection. The knowledge and information of Purchaser is not required to exceed that which is normally possessed by a prudent person in the ordinary course of business dealings. If Purchaser knowingly enters into a timber sale transaction with a person who is proposed for debarment under 48 CFR 9.4, suspended, debarred, ineligible, or voluntarily excluded from participation in covered transactions or timber sales, in addition to other remedies available to the Government, Forest Service may pursue available remedies, including suspension and/or debarment. Contracting Officer shall provide a copy of Forms AD-1047 Certification Regarding Debarment, Suspension and Other Responsibility Matters – Primary Covered Transactions and AD-1048 Certification Regarding Debarment, Suspension, Ineligibility and Voluntary Exclusion – Lower Tier Covered Transactions to the Purchaser. Purchaser shall complete form AD-1047 and provide to the Contracting Officer upon request. Purchaser shall require each subcontractor to complete form AD-1048 and provide to the Contracting Officer upon request.

  • Blasting Blasting shall be permitted only for road construction purposes unless advance permission is obtained from Forest Service. Whenever the Industrial Fire Precaution Level is II or greater, a fire security person equipped with a long handled round point No. 0 or larger shovel and a 5 gallon backpack pump can filled with water, will stay at location of blast for 1 hour after blasting is done. Blasting may be suspended by Forest Service, in areas of high rate of spread and resistance to control. Fuses shall not be used for blasting. Explosive cords shall not be used without permission of Forest Service, which may specify conditions under which such explosives may be used and precautions to be taken.

  • Scaling “Scaling,” as used herein, involves:

  • Fabrication Making up data or results and recording or reporting them.

  • Intake Intake begins when you, or someone on your behalf, contacts the LIFE Provider or the Independent Enrollment Broker expressing interest in services. If it appears from this first conversation that you are potentially eligible, a LIFE Provider and Independent Enrollment Broker representative will contact you to explain the program, obtain further information about you, and to schedule in person or tele-visits. During these visits: • You will learn how the LIFE Program works, the services LIFE offers, and the answers to any questions you may have about LIFE. • The LIFE Provider and/or Independent Enrollment Broker will explain that if you enroll, you must agree that all of your healthcare services will be provided and/or coordinated by LIFE, including primary care and specialist physician services (other than emergency services). • The LIFE Provider will have you sign a release allowing the LIFE Provider to obtain your past medical records so the LIFE health team can fully assess your health conditions. You will be encouraged to visit the LIFE Center to see what it is like. If you are interested in enrolling, a LIFE Provider representative and the Independent Enrollment Broker will assist you with the enrollment process. You should be prepared to participate in phone calls and/or visits with both the LIFE Provider and Independent Enrollment Broker in order to complete your enrollment process.