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A total of 1764 fracture mechanics tests were conducted on fourteen alloys to develop property data for use in the B-1 design. Tests were performed on aluminum alloys 2024, 2124, 2219, 7049, 7050, 7075 and 7175; titanium alloy Ti-6Al-4v; steel alloys 9Ni-4Co-.20C, 9Ni-4Co-.30c and 300M; corrosion resistant steel PH13-8Mo; nickel alloy Inconel 718; and nickel-cobalt alloy MP 35 N. The effects of product form, heat-to-heat variability, grain orientation, and heat treat condition on fracture behavior were investigated. In addition, the fracture properties of welds in Ti-6Al-4v, PH13-8Mo and 9-4-.20 alloys and of diffusion bonds in Ti-6Al-4v were determined. Testing variables were temperature, specimen thickness, environment, cyclic frequency and R factor for the da/dN tests. The results of the tests are presented in tables and graphs in detailed and summarized forms. The effects of the various material and testing variables on fracture behavior are discussed., See also Volume 2, AD-A039 785.

A total of 1764 fracture mechanics tests were conducted on fourteen alloys to develop property data for use in the B-1 design. Tests were performed on aluminum alloys 2024, 2124, 2219, 7049, 7050, 7075 and 7175; titanium alloy Ti-6Al-4V; steel alloys 9Ni-4C0-.20C, 9Ni-4C0-.30c and 300M; corrosion resistant steel PH13-8Mo; nickel alloy Inconel 718; and nickel-cobalt alloy MP 35N. The effects of product form, heat-to-heat variability, grain orientation, and heat treat condition on fracture behavior were investigated. The results of the tests are presented in tables and graphs in detailed and summarized forms. The effects of the various material and testing variables on fracture behavior are discussed., See also Volume 1, ADA039883.

This is the final engineering report for a Naval Air Systems Command sponsored program to evaluate the forgeability characteristics of CORONA-5, a new titanium alloy with a nominal composition of Ti-4.5Al-5Mo-1.5Cr. The goal of this contract was to define forging and final heat treat parameters which would produce optimum or near-optimum toughness over the strength range of 130-140 ksi (about 900-965 MPa), UTS. During this program, a total of six different forging sequences were evaluated to identify effects of varying degrees of alpha/beta working on resultant microstructures and attendant mechanical properties. In addition, two different final heat treat cycles were employed to provide strength variations over the goal range. The results of these evaluations indicated that the best combinations of strength and toughness were produced by forging the material above its beta transus or at temperatures high in the alpha plus beta region.

The goals of this program were to develop titanium alloy(s) having fracture toughness/strength characteristics which, in combination, exceeded the properties of current commercially available alloys. The goal properties were a tensile strength (UTS) of 135 ksi at a toughness of 100 ksi in. and/or UTS of 170 ksi with a toughness of 80 ksi in. This effort consisted of two consecutive phases. Phase I included the preparation and evaluation of twenty pound heats of twenty different alloy compositions and five pound heats of two additional alloy compositions, in order to select one or two compositions having the potential of achieving the contract strength-toughness goals. Phase II included a scale-up of the two alloys (Ti 5Mo 4.5Al 1.5Cr and Ti 8Mo 2.5Al 1.5Cr) selected from Phase I to larger (500 pound) ingots. These larger ingots were then processed through a variety of processing sequences designed to produce a range of microstructures and properties. Extensive property evaluations were then performed on several microstructural conditions.

This is the final engineering report for a Naval Air Systems Command sponsored program to develop new titanium alloys for aircraft applications. During the first of the two phases in this effort, four thermomechanical processing/final heat treatment sequences were evaluated for each alloy. Evaluations at the conclusion of this phase revealed that mechanical properties of three of the four process conditions investigated for Ti-5Mo-4.5Al-1.5Cr met or exceeded the high toughness/moderate strength goal, indicating good reproducibility of these properties over a wide range of processing conditions. On the other hand, mechanical properties of the alloy designed to meet the moderate toughness goal at high strength levels, Ti-8Mo-2.5Al-4.5Cr, fell short of those goals. Because of a real need to develop an alloy of this type, particularly for forging applications, the second phase of this effort was concentrated on further development of this latter alloy.

In the Eastern Goldfields of Western Australia, use of a front-end loader to remove the top metre of earth and waste is being applied in conjunction with metal detectors to locate the remaining alluvial gold in areas where the surface has already been cleared by earlier prospectors or by local people or tourists. The results of such "pushing" can range from 5 g to 10 kg Au per location. Operating costs are around Aus, In the Eastern Goldfields of Western Australia, use of a front-end loader to remove the top metre of earth and waste is being applied in conjunction with metal detectors to locate the remaining alluvial gold in areas where the surface has already been cleared by earlier prospectors or by local people or tourists. The results of such "pushing" can range from 5 g to 10 kg Au per location. Operating costs are around Aus

Exploration licences in Papua New Guinea total more than 260 and are held by 79 companies from seven different countries, with a further 20 licences under renewal and more than 100 new applications. Au remains the main commodity, with Cu, Ni, Fe and seabed massive sulphides also being targeted. Projects reviewed include the Hidden Valley operation, where the first Au was poured in June 2010 and annual production is expected to peak at 275 000 oz in 2019, a Cu-Au-Mo prospect on the island of New Britain which involves three tenements at Simuku, Mount Nakru and Talelumas, the Ramu Ni-Co laterite project and the Frieda River Cu-Au project, where a pre-feasibility study is being undertaken and annual production targets are 31 150 t Ni and 3 300 t of Co over an initial 20- year mine life. Project expansions being undertaken or planned include Lihir, where output is expected to increase to about 1 000 000 oz/y from 2012, Porgera, where current reserves are sufficient to support surface and underground Au mining until 2017, and Ok Tedi, where efforts are being made to find additional resources. A more than 1 000 000 oz Au resource has been identified on Woodlark Island, and the total resources at the mine on Simberi Island have been increased to 4 700 000 oz Au and 10 000 000 oz Ag. Other resources being evaluated include laterite Ni-Co deposits at Wowo Gap, the Salamua chromite prospect, the Amazon Bay iron sands prospect and the Solwara 1 Au-Cu-Ag sea floor deposits. Small-scale alluvial Au mining is an important source of income and a training and management programme has been put into place. Oil and gas exploration and production operations are also reviewed., Exploration licences in Papua New Guinea total more than 260 and are held by 79 companies from seven different countries, with a further 20 licences under renewal and more than 100 new applications. Au remains the main commodity, with Cu, Ni, Fe and seabed massive sulphides also being targeted. Projects reviewed include the Hidden Valley operation, where the first Au was poured in June 2010 and annual production is expected to peak at 275 000 oz in 2019, a Cu-Au-Mo prospect on the island of New Britain which involves three tenements at Simuku, Mount Nakru and Talelumas, the Ramu Ni-Co laterite project and the Frieda River Cu-Au project, where a pre-feasibility study is being undertaken and annual production targets are 31 150 t Ni and 3 300 t of Co over an initial 20- year mine life. Project expansions being undertaken or planned include Lihir, where output is expected to increase to about 1 000 000 oz/y from 2012, Porgera, where current reserves are sufficient to support surface and underground Au mining until 2017, and Ok Tedi, where efforts are being made to find additional resources. A more than 1 000 000 oz Au resource has been identified on Woodlark Island, and the total resources at the mine on Simberi Island have been increased to 4 700 000 oz Au and 10 000 000 oz Ag. Other resources being evaluated include laterite Ni-Co deposits at Wowo Gap, the Salamua chromite prospect, the Amazon Bay iron sands prospect and the Solwara 1 Au-Cu-Ag sea floor deposits. Small-scale alluvial Au mining is an important source of income and a training and management programme has been put into place. Oil and gas exploration and production operations are also reviewed.

A-Cap Resources has two U prospects in Botswana, Letlhakane and Serule, with the latter in an earlier stage of exploration. The U3O8 resources are 116 000 000 and 42 000 000 lb, respectively, and the ore grades are similar. The resource at Letlhakane includes secondary, oxide and primary mineralisation, with the metallurgy providing more than 90%, 80% and 50% recoveries, respectively. A series of very large shallow pits is envisaged, with heap leaching being used to process the ore. A bankable feasibility study is scheduled to be completed in 2010., A-Cap Resources has two U prospects in Botswana, Letlhakane and Serule, with the latter in an earlier stage of exploration. The U3O8 resources are 116 000 000 and 42 000 000 lb, respectively, and the ore grades are similar. The resource at Letlhakane includes secondary, oxide and primary mineralisation, with the metallurgy providing more than 90%, 80% and 50% recoveries, respectively. A series of very large shallow pits is envisaged, with heap leaching being used to process the ore. A bankable feasibility study is scheduled to be completed in 2010.

Feasibility studies are currently being carried out at Galaxy Resources' Mount Cattlin Ta and Li prospect in Western Australia. A pre- feasibility study has indicated an open-pit operation with a mine life of 10 years at a mining and processing rate of 1 000 000 tpa to produce 140 000 t of spodumene concentrate plus about 200 t of tantalum pentoxide in concentrate. Global Li2CO3 demand increased by 7.4% to 93 000 t in 2007, with increasing use in lithium ion batteries, and the company is investigating the production of Li2CO3 from the Mount Cattlin spodumene concentrate., Feasibility studies are currently being carried out at Galaxy Resources' Mount Cattlin Ta and Li prospect in Western Australia. A pre- feasibility study has indicated an open-pit operation with a mine life of 10 years at a mining and processing rate of 1 000 000 tpa to produce 140 000 t of spodumene concentrate plus about 200 t of tantalum pentoxide in concentrate. Global Li2CO3 demand increased by 7.4% to 93 000 t in 2007, with increasing use in lithium ion batteries, and the company is investigating the production of Li2CO3 from the Mount Cattlin spodumene concentrate.

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Contents have not been copyrighted, https://egrove.olemiss.edu/dl_proceedings/1058/thumbnail.jpg

Contents have not been copyrighted, https://egrove.olemiss.edu/dl_proceedings/1058/thumbnail.jpg

Contents have not been copyrighted, https://egrove.olemiss.edu/dl_proceedings/1058/thumbnail.jpg