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THE PREPARATION AND PROPERTIES OF THREE REFRACTORY BERYLLIDES

Description: The beryllium compounds NbBe/sub 12/, YBe/sub 13/, and ZrBe/sub 12/ were prepared by arc melting. Some beryllium was lost in this operation but sound ingots were obtained. The hardness, density, metallographic structure, x-ray structure, and oxidation resistance in air of each ingot were determined. The zirconium compound apparently had a tetragonal structure corresponding to ZrBe/ sub 12/ and a hardness of 790 Knoop and a density of 2.94 g per cm/sup 3/. The yttrium compound had a cubic structure corresponding to YBe/sub 13/ and a hardness of 570 Knoop and a density of 2.57 g per cm/sup 3/. The niobium compound had a tetragonal structure corresponding to NbBe/sub 12/ and a hardness of 1100 Knoop and a density of 3.14 g pre cm/sup 3/. The zirconium alloy was most difficult to prepare and crumbled at 700 deg C during oxidation testing. The niobium and yttrium alloys were both relatively easy to prepare and both were highly resistant to oxidation at 1300 deg C. The niobium alloy had the most satisfactory behavior in all respects and appears most promising for further development. (auth)
Date: March 1, 1959
Creator: Chubb, W. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

CHARACTERIZATION OF INCLUSIONS IN DINGOT URANIUM

Description: The nonmetallic inclusions in both as-reduced and fabricated dingot U were studied for comparison with those in ingot U. Special attention was paid to the hydride for the purpose of determining the amount and distribution in the various types of U. The types and distribution of other inclusions were also studied. It wss found tbat the dingot U was of a higher quality than ingot U and was comparable to as-reduced derby U on the basis of over-all inclusion count. The H content in dingot U, however, was found to be appreciably higher than in either ingot or derby U. (auth)
Date: January 11, 1957
Creator: Cheney, D.M. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

PROGRESS RELATING TO CIVILIAN APPLICATIONS DURING JUNE 1962

Description: >Progress is reported on reactor materials and components, studies of fuels, general fuel-element development, preparation of UO/sub 2/ single crystals, radioisotope and radiation applications, materials development and evaluation, coated-particie fuel materials, corrosion studies of Fluoride Volatility Process, progress on USAEC/AECL cooperative program, fission-product deposition studies, radiationeffects study of candidate fuel materials for MGCR, gascooled reactor program, process development and evaluation of properties of F- 48 niobium alloy, and gas pressure bonding of beryllium-clad elements. (M.C.G.)
Date: July 1, 1962
Creator: Dayton, R.W. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

PREPARATION AND EVALUATION OF ALUMINUM-35 w/o URANIUM ALLOYS CONTAINING UP TO 3 w/o TIN OR ZIRCONIUM

Description: The effects of ternary additions of up to 3 wt.% Sn or Zr to an Al-35 wt.% U extrusion alloy were evaluated on the basis of casting characteristics, UAl/sub 3/ retention, extrusion behavior, mechanical properties, and corrosion resistance. Both additions increased the fluidity of the alloy, and both promoted retention of UAl/sub 3/. The best fluidity was obtained by a 2 wt.% Sn addition, while Zr was the more effective stabilizer of UAl/sub 3/. The retention of UAl/sub 3/ decreased the extrusion pressure needed for fabrication and caused a corresponding decrease in tensile and creep-rupture properties. Reductions in strength were most noticeable at elevated temperatures. The 1000- hr stress-rupture strength of the binary alloy at 200 deg C (8300 psi) was approximately 25 and 11% higher, respectively, than the alloys containing 3 wt.% tin (6200 psi and 3 wt.% zirconium (7400 psi). The additions either slightly improved or had no effect upon the resistance of the Al-35 wt.% alloy in 150 deg C demineralized water. (auth)
Date: July 29, 1960
Creator: Daniel, N.E.; Foster, E.L. Jr. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

EFFECTS OF TERNARY ADDITIONS OF ALUMINUM-35 w/o URANIUM ALLOYS

Description: The effects of a number of ternary additions on the constitution, casting, and fabricating characteristics and the physical properties of aluminum- 35 wt.% uranium were investigated. Initial investigations were concerned with the effects of 3 at.% ternary additions on the microstructure and press-forging characteristics of the alloy. It was found that additions of this magnitude often introduced extrinsic phases in the alloy. At the 3 wt% level, additions of germanium, silicon, tin, or zirconium inhibited the formation of UAl/sub 4/ and thereby increased the extent of the aluminum matrix in the alloy. It was also noted that these additions decreased the pressures required for extruding, and the tin addition also improved the homogeneity of cast shapes. Lead and palladium also improved the homogeneity of the cast material; however, neither of these was an effective inhibitor of UAl/sub 4/ and free lead was detected in the alloy to which lead had been added as the ternary. From these studies it appears that tin and zirconium are as effective as silicon in enhancing the fabricating characteristics of rior when evaluated on the bases of casting qualities and recycling characteristics. (auth)
Date: October 27, 1959
Creator: Daniel, N.E.; Foster, E.L. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF HIGH-STRENGTH NIOBIUM ALLOYS FOR ELEVATED-TEMPERATURE APPLICATIONS

Description: A study to improve the elevated-temperature strength of niobium by solloving has resulted not only- in greatly improved strengths at 1200 and 1470 deg F but also in the development of improved fabrication techniques for these alloys. The most important step in the fabric:ition procedure of niobium and niobium-base allows is the initial breakdown of the cast structure. The cast structure of 1.84 wt. 4 chromium, 3.21 wt.% chromium. 4.33 wt. ' zirconium, and 20.5 wt.% titanium-4.28 wt. = chromium allovs and unalloyed niobium was broken known by- forging ingots (protected from oxidation by molybdenum ciins) at 2550 deg F and rolling at 800 deg F. After the initiai breakdown of the cast structure, the alloy-s were coid roiied to a total of 95 per cent reduction with no difficulty .A second fabrication technique was employed for a second set of alloys. Unalloyed niobium and 1.29 wt. % chromium, 2.74 wt. 3 zirconium, 4.5 wt.% molybdenum, and 10 wt. % titanium-3 wt.% chromium alloys were forged and rolled at 1000 deg F to break down the cast structure and then cold rolled to 0.030-in. sheet. the sheet obtained by this technique showed moderate edge cracking. Tensite tests on the coid-worked materiais at 1200 and 1470 deg F indicate that chromium and zirconium.ire both potent strengtheners of niobium: the 1.84 wt.% chromium alloy- hiid a 0.2 per cent offset yield strength of 107,000 psi at 1200 deg F and 69,000 psi at 1470 deg F, and the 4.33 wt. % zirconium alloy had a 0.2 per cent offset yield strength of 69,000 psi at 1470 deg F. Limited welding studies indicate that strong and reasonably ductlle welds can be produced both by arc and spot welding. (auth)
Date: February 22, 1960
Creator: De Mastry, J.A.; Shober, F.R. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF THORIUM-URANIUM-BASE FUEL ALLOYS

Description: Thorium-uranium alloys were studied with the aim of developing alloys with improved irradiation behavior by control of microstructure. The effect of thorium purity, melting technique, hot and cold working, and heat treatment on microstructure was investigated. The most signifi- . cant microstructural differences occurred as a result of casting technique, The arc-melted alloys exhibited the most nearly ideal structure, that of a homogeneous dispersion of small-diameter uranium particles in a thorium matrix, In addition, the rate of work hardening, recrystallization behavior, density, and hot hardness of thoriumuranium alloys were determined. As uranium content increases, the rate of work hardening increases, The recrystallization temperature of thorium was found to increase by over 100 deg C when uranium is present. Molybdenum, niobium, zirconium, and zirconium in conjunction with niobium were added to thorium- uranium with the aim of increasing irradiation resistance by stabilizing the gamma-uranium phase and/or improving the hightemperature strength of the alloy. It was found that small additions of molybdenum or niobium were effective in stabliizing the gamma-uranium phase, while zirconium was an effective hardener at temperatures up to 600 deg C, Zirconium additions to thorium-uranium alloys were effective in improving the 300 deg C water corrosion resistance of thorium by a factor of two. (auth)
Date: March 18, 1960
Creator: Farkas, M.S.; Bauer, A.A. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

CENTRIFUGAL CASTING OF ALUMINUM-URANIUM ALLOYS

Description: Centrifugal-casting techniques were investigated as a method of producing hollow cylindrical extrusion billets of aluminum-35 wt.% uranium. Among the variables evaluated were melt temperature, mold and pouring-spout configurations, mold speed, and method of pouring. With the equipment employed it was found that the best castings were produced utilizing a pouring temperature of 2400 ction prod- , a heavy-walled steel cylinder rotating between 700 and 900 rpm for the mold and a bottom-pouring technique employing a retractable pouring spout. Sound, nonporous billets 26 in. long and 5 in. in diameter were produced with a yield after machining of over 75% of the original charge. The major losses occurred in the pouring spout-and-cup asserably. This loss is relatively unaffected by the casting length; and, therefore, castings of greater length than 26 in. should result in even greater recoveries. (auth)
Date: July 20, 1959
Creator: Daniel, N.E.; Foster, E.L. Jr. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

Effects of Yttrium on the Fabrication and Tensile Properties of Two Modified Stainless Alloys

Description: Alloys containing 55 wt.% iron--22 wt.% nickel-- 17 wt.% chromium--2.5 wt.% molybdenum- 1.0 wt.% niobium-0.03 wt.% carbon-- 0.5 wt.% manganese-- 0.5 wt.% silicon with nominal additions of from 0 to 1.5 wt.% yttrium, and 36 wt.% iron-37 wt.% nickel--18 wt.% chromium--2.5 wt.% molvbdenum- 1.5 wt.% niobium-- 1.0 wt.% aluminum-0.05 wt.% carbon--0.5 wt.% manganese-- 0.5 wt.% silicon with nominal additions of from 0 to 2.0 wt.% yttrium, were prepared by vacuum- induction melting. Alloys containing 55 wt.% iron were successfully forged in air at 1900 deg F, rolled at 1850 deg F to 0.060-in. sheet and cold rolled to 0.015in. sheet. Fabrication of alloys containing 36 wt.% iron with more than 0.5 wt.% yttrium was unsuccessful. Addition of yttrium had relatively no effect on the yield and ultimate strength from room temperature to 1850 deg F. The ductility of fabricable alloys studied was increased at elevated temperatures by increasing yttrium contents. The greatest increase in ductility occurred at 1.5 wt.% yttrium. (auth)
Date: February 24, 1960
Creator: DeMastry, J. A.; Shober, F. R. & Dickerson, R. F.
Partner: UNT Libraries Government Documents Department

Solubility Limits of Yttrium and the Lanthanide Rare-Earth Elements in Chromium and Chromium-Iron Alloys

Description: The solubility limits of yttrium and the lanthanide rareearth elements in chromium and chromium-iron alloys were investigated at 2300 deg F and at room temperature. Bases of pure chromium and chromium alloyed with 10, 25, 50, and 75 wt.% iron were prepared with additions of cerium, dysprosium, erbium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, samarium, terbium, thulium, ytterbium, and yttrium. Most of the elements investigated are estimated to be soluble to the extent of 0.1 wt.% or less in the base alloys. Dysprosium, erbium, and holmium exhibit solubility limits estimated to be between 0.1 and 0.3 wt.%. In general, the solubilities of these elements decreased slightly from 2300 deg F to room temperature. (auth)
Date: September 1, 1959
Creator: Epstein, S. G.; Bauer, A. A. & Dickerson, R. F.
Partner: UNT Libraries Government Documents Department

Development of High-Strength Corrosion-Resistant Zirconium Alloys

Description: Approximately 100 ternary and quaternary spongezirconium alloys were screened for structural and cladding applications in a natural-uranium-fueled heavy-watermolerated power reactor. The alloy additions studied included2 to 4 wt.% Sn, 0.5 to 2 wt.% Mo, and 1 to 3 wt.% Nb. The effect of 0.1 wt.% Fe and 0.05 wt.% Ni additions to the experimental alloys was evaluated. All compositions were are melted, rolled at 850 ction prod- C from a helium- atmosphere furnace, vacuum annealed 4 hr at 700 ction prod- C, and furnace cooled. Room- and elevated-temperature hardness measurements were used to estimate the tensile strengths of the alloys, while corrosion resistance was evaluated by 1000-hr exposures to static 300 ction prod- C water. (auth)
Date: February 22, 1960
Creator: De Mastry, J. A.; Shober, F. R. & Dickerson, R. F.
Partner: UNT Libraries Government Documents Department

PREPARATION AND PROPERTIES OF URANIUM MONOCARBIDE CASTINGS

Description: Using a special arc-melting technique, sound, homogeneous 100-g cylindrical castings of UC of near stoichi ometric composition were consistently produced. In the casting process developed, UC buttons previously prepared by arc melting the elements were placed over the opening of a graphite mold in a helium-atmosphere arc furnace. When the UC button became fully molten under the arc, it dropped by gravity into the mold. The densities of the resultant castings were about 95% of theoretical. The castings could be successfully machine ground using a water-base cutting fluid. In a preliminary determination of some physical properties of cast UC, the thermal conductivity measured at 100, 400, and 700 deg C was 0.060, 0.053, and 0.060 cal/(sec)(cm)(C), respectively. The mean linear- thermal-expansion coefficient in the temperature range from 20 to 95o deg C was 11.4 x 10/sup -6/ per C. Cast UC encapsuled in stainless steel exhibited good resistance to thermal stress and shock in two series of tests of 100 thermal cycles to 90WC and 100 cycles to 1100 deg C. Heat treating a casting specimen for 1 hr at 1000 deg C produced no significant change in microstructure, but after a subsequent exposure of 1 hr at 1500 deg C hardening and the appearance of the U/sub 2/C/sub 3/ phase were evident. In tests of compressive strength on a single specimen rupture occurred at 54,500 psi. (auth)
Date: January 1, 1959
Creator: Secrest, A.C. Jr.; Foster, E.L. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

SURVEY OF TERNARY AND QUATERNARY METASTABLE GAMMA-PHASE URANIUM ALLOYS

Description: A survey of the effects of ternary and quaternary alloying on the stability and properties of uranium-zirconium, -- niobium, and -- molybdenum-base gammaphase alloys was conducted. The effects of ternary and quaternary additions of chromium, molybdenum, niobium, ruthenium, vanndium, and zirconium on transformation kinetics, transformation temperature, hot hardness, and corrosion resistance were investigated. Niobium or molybdenum additions to uranium-- zirconium-base alloys increased thermal stability and hot hardness of the gamma phase and lowered transformation temperatures. Those additions also generalty resulted in improved corrosion resistance. Zirconium increased the gamma-phase stability in uranium-niobium-base alloys, lowered transformation temperatures, and in some amounts increased hot hardness and improved corrosion resistance. Variable corrosion behavior of the uranium--niobium-- zirconium alloys is probably attributable to lack of homogeneity. Molybenum additions had either a negligible or detrimental effect on the thermal stability of the uranium-- niobium gamma phase, although molybdenum did lower the temperature at which alpha uranium begins to decompose on heating. The addition of 1 wt. % molybdenum to the 10 wt. % niobium alloy or 3 wt. % molybdenum to the 20 wt. % niobium alloy resulted in maximum hardness of the gamma phase at elevated temperatures, the hot hardness decreasing with larger aditions. Generally little effect of molybdenum on the corrosion resistance of uranium- niobium-base alloys was noted, although a 3 wt. % addition was found to increase the corrosion life of the 10 wt.% niobium alloy. Niobium additions of up to 3 wt.% to the 7.5 wt. % molybdenum-base alloy and of 1 wt. % to the 10 and 12 wt. % molybdenum-base alloy; increase the thermal stability of the gamma phase; larger niobium additions decreased stability. A possible slight increase in the temperature of gamma formation on heating accompanied the addition of niobium. Ruthenium increased gamma stability more effectively, while it depressed ...
Date: July 15, 1958
Creator: Storhok, V.W.; Bauer, A.A. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

THE TENSILE STRENGTH OF SOLID-STATE BONDED ALUMINUM AND NICKEL-PLATED URANIUM

Description: To aid in the evaluation of solid-state bending techniques for cladding natural-uranium fuel-element cores with aluminum, tensile specimens, 1/4 in. in diameter and 3 in. long were made and tested. Results show that these techniques are capable of producing satisfactory bonds between aluminum and nickel-plated uranium. Pressing conditions of 1 min at 950F and 6000 psi produced consintent bond strengths equal to the yield strength of 25 aluminum. When optimum bonding conditions are used, anodic activation and strike-current density are not critical to bond strength. Nickel plating of the aluminum component of the bond couple reduced the tensile strength by about 50%. (auth)
Date: October 21, 1954
Creator: Saller, H.A.; Dickerson, R.F. & Carlson, R.J.
Partner: UNT Libraries Government Documents Department

THE EXAMINATION AND EVALUATION OF IRRADIATED THORIUM-11 w/o URANIUM SPECIMENS

Description: Twelve irradiated specimens of thorium -11 wt.% U were examined. The specimens were fabricated by induction melting and casting in graphite and cold swaging to about 42% reduction in area. The irradiations were conducted in the MTR in capsules equipped with thermocouples. Six specimcns were irradiated to burnups ranging from 0.5 to 0.6 total at.% at average central corc temperatures ranging from 1070 to 1250 F. Three spccimens exbibited sevcre swelling or decrepitation and three appeared to be in relatively good condition. The density of these specimens decreased from 4.9 to 9.9%. The remaining six specimens were irradiated to burnups ranging from 0.9 to 1.5 total at.% at average central core temperatures ranging from 970 to 1100 F. These specimens were in relatively good condition, except for three that had swollen sevcrely at one end. Density decreases ranging from 2.4 to 3.8% were determined for these specimens. Swelling of all specimens appeared to be a linear function of burnup to the highest level studied (l.5 total at.%) and at temperatures below about 1100 F. Swelling increased significantly above 1100 F, even at burnups as low as 0.2 at.%. Fission-gas losses averaged about 0.5% for sound specimens after burnups of 1.2 to 3.3 total at.% at around l100 F. These losses were due to diffusion and recoil; cracked specimens exhibited higher losses, Metallographic examination of the specimens indicated that neither thc matrix material nor the fuel material was seriously affected by the irradiation. No evidence of corrosion by the NaK heat-transfer medium was present. (auth)
Date: April 16, 1959
Creator: Gates, J.E.; Lamale, G.E. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

EFFECTS OF IRRADIATION ON STAINLESS STEEL-CLAD UO$sup 2$ PELLETS IN HELIUM OR CARBON DIOXIDE

Description: Uranium dioxide pellets sealed in Type 316 stainless steel containers with a helium gas were irradiated in helium and in C0/sub 2/ in thermal fluxes or the order of 1 x 10/sup 13/ n/(cm/sup 2/)(sec). Cladding-surface temperatures were reportedly between 1200 and about 1800 F. The hot-cell examination performed by BMI showed that there were no obvious effects of the irradiation on the specimen tested in helium. However, the specimen irradiated in the presence of C0/sub 2/ exhibited severe cladding-CO/sub 2/ reaction and possible central melting of the UO/sub 2/. Although comparisons between pre- and postirradiation data were difficult because of involved fabrication history of the specimens, the tests did further establish the fact that helium is a satisfactory coolant gas for stainless steel cladding material at a temperature of 1200 F. The data obtained from the specimen tested in the presence of C0/sub 2/ indicate that at temperatures in the range of 1600 to 1800 F Type 316 stainless steel is not compatible with C0/sub 2/. (auth)
Date: April 21, 1959
Creator: Lamale, G.E.; Gates, J.E. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

A STUDY OF THE LIQUIDUS IN ALUMINUM-URANIUM ALLOYS

Description: Liquidus temperatures in the aluminum -uranium system have been redetermined for alloys containing 13 to 50 wt. % uranium. Thermal analysis, electricalresistance measurements, and metallography were employed in the investigation. The binary aluminumuranium alloys studied and, their corresponding liquidus temperatures are as follows: 17 wt. % uranium, 755 deg C; 17.5 wt. % uranium, 780 deg C; 24.5 wt. % uranium, 954 deg C; 30.9 wt. % uranium, 1068 deg C; 41.6 wt. % uranium, 1190 deg C; 51.2 wt. % uranium, 1265 deg C. Eutectic and peritectic temperatures were determined to be at 640 and 732 deg C, respectively. Binary alloys containing ternary addition of up to 1 wt. % silicon and up to 0.5 wt. % magnesium were studied also. Neither silicon nor magnesium were found to have any effect on the liquidus temperatures. However, silicon lowered the peritectic temperature from 732 to 700 deg C and among alloys coataining less than 30 wt. % uranium had a refining effect on eutectic UAl/sub 4/ particles. The only effect that could be attributed to the magnesium addition was a tendency toward coarsening the UAl/sub 4/ particles in alloys containing less than 30 wt. % uranium. (auth)
Date: May 1, 1958
Creator: Storhok, V.W.; Bauer, A.A. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

High-Temperature Oxidation Resistance of Thin Iron-Chromium-Aluminum Alloy Sheet

Description: S>The oxidation resistance of thin sheets of Fe - 28 wt. % Cr - 2.67 to 10.0 wt. % Al alloys, nominally 0.004, 0.006, 0.008, 0.012, and 0.016 in. thick, was determined by exposure in static air for 100 hr at 2100 and 2300 deg F. A minimum of 3.67 and 9.37 wt.% Al was necessary to prevent excessive oxidation of 0.004-in. thick sheet material at 2100 and 2300 deg F, respectively. Specimens of lower Al content and greater thickness withstood oxidation attack. Oxidation of Fe - Cr - Al alloys apperars to be related to the diffusion of Al to surfaces of the sheet to form an adherent protective layer of Al/sub 2/ O/sub 3/.(auth)
Date: October 22, 1957
Creator: Jablonowski, E. J.; Shober, F. R. & Dickerson, R. F.
Partner: UNT Libraries Government Documents Department

EXPERIMENTS TO DETERMINE THE RADIATION STABILITY OF UN DISPERSIONS IN STAINLESS STEEL

Description: A controlled radiation experiment was performed to determine the stability of fuel containing 28 wt.% UN dispersed in and clad with Type 318 stainless steel as compared with fuel containing 30 wt.% UO/sub 2/ dispersed in the same material. The specimens were prepared by hot rolling the fuel coupons in Type 318 stainless steel using the picture-frame technique for initial bonding and reduction. Final dimensions were obtained by cold rolling. A special radiation capsule was designed which contained heat control and enough thermocouples to ensure a good continuoustemperature history throughout the test. This capsule and the method by which the specimens were loaded are discussed in some detail. Because of the capsule instrumentatton. the known MTR position into which the capsule was placed. and the dostmeters placed tn the capsule it was possible to obtain a complete flux and temperature history of the capsule during the irradiation. When it was estimated that the specimen burnup was about 7.2 at.% of uranium-235 the capsule was removed from the reactor and returned to the Battelle Hot-Cell Facility. The postirradiation examination which consisted of fission-gas analysis, density and dimensional determinations, radiochemical and isotropic burnup analysis, and metallography is discussed completely in the report. The results of the various phases of the experiment are discussed and conclusions are drawn on the basis of an integrated evaluation. These results indicate that the UN dispersions withstood irradiation at temperatures of 1500 to 2000 tained F and at burnups of 3.5 to 5.0 at.% of the uranium-235 at least as well as the UO/sub 2/ dispersions. These conclusions indicate the potential of UN as a high-temperature fuel, however, it is also obvious that many additional radiation experiments are required. (auth)
Date: June 14, 1960
Creator: Gates, J.E.; Freas, D.G.; Saling, J.H. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

STUDIES FOR THE PREPARATION OF ZIRCONIUM-CLAD URANIUM-10 w/o MOLYBDENUM FUEL PINS

Description: Production methods for producting homogeneous uranium-10 wt.% molybdenum fuel-alloy pin with a uniform zirconium cladding have been studied. The effect of various impurities has been investigated and the nature of and methods for ellminating cracking in swaged fuel pins have been examined. A major portion of the results is based on the study of material produced from 25-lb ingot castings. Small expertmental-scale ingots were also employed in impurity, heat-treatment, and cracking studies. On the basis of the data obtained recommendattons concerning casting, fabrication, and heat-treatment techniques necessary to produce a fuel pin of satisfactory integrity are presented. Specifications as to allowable carbon, chromium, iron, nickel, oxygen, and zirconium content are recommended. (auth)
Date: October 27, 1958
Creator: Fox, J.B.; Cheney, D.M.; Bauer, A.A. & Dickerson, R.F.
Partner: UNT Libraries Government Documents Department

Effects of Irradiation on the Mechanical Properties of Tantalum

Description: Tensile, bend ductility, and hardness tests were performed at room temperature on irradiated tantalum sheet to determine the effect of irradiation on the strength and ductility. Sheet tensile specimens were irradiated in an attempt to produce corversions of tantalum to tungsten of approximately 1.5 and 3.0 wt.%. Unirradiated tantalum and arc-melted alloys of tantalum-1.5 and -3 wt.% tungsten were tested for comparison with the irradiated material. The tensile and yield strengths of tantalum were found to increase appreciably as a result of irradiation whereas the tensile properties of unirradiated Ta-W alloys prepared by arc melting showed that small additions of tungsten do not signicantly increase the strength of tantalum. These results indicate that the major part of the increase in strength resulting from irradiation of tantalum can be attributed to fast-neutron damage and that any contribution produced by the conversion of tantalum to tungsten is a minor one. (auth)
Date: November 18, 1960
Creator: Franklin, C. K.; Stahl, D.; Shober, F. R. & Dickerson, R. F.
Partner: UNT Libraries Government Documents Department