Ed Royce | University of California, Davis (original) (raw)
Papers by Ed Royce
Shock compression of the stainless uranium alloy mulberry (rho/sub 0/ = 16.4 g/cm/sup 3/) has bee... more Shock compression of the stainless uranium alloy mulberry (rho/sub 0/ = 16.4 g/cm/sup 3/) has been observed through use of inclined prisms. No Hugoniot elastic limit was apparent; both pressure and shock velocity (U/sub s/) rise continuously with compression. The propagation velocity rises slowly for values of particle velocity (U/sub p/) between 0 and 0.4 mm/..mu..s and then rises more rapidly. The equations for the line segments which approximate the (U/sub s/, U/sub p/) curve are U/sub s/ = 2.92 + 0.63U/sub p/ for U/sub p/ 0.4 mm/..mu..s.
Physical Review B
and Hf. It is deduced that only Ce exhibits phenomena that may be related to a 4f M electronic ph... more and Hf. It is deduced that only Ce exhibits phenomena that may be related to a 4f M electronic phase transition. An abrupt decrease in compressibility at at high pressure is taken to be evidence of the onset of interaction between closed electron shells in metals. This work is the first identification of the closed-shell electronic interactions in metals in a high-pressure experiment.
A three-phase equation of state for metals is developed, based on the following assumptions: (1) ... more A three-phase equation of state for metals is developed, based on the following assumptions: (1) t h e entropy of melting is independent of pressure; (2) the temperature dependence of the specific heat in the liquid is a universal curve, scaled on the melting temperature; (3) the p r e s s u r e dependence of the melting temperature is given by a modified Lindemam law; and (4) the liquid-vapor region may be described by a hard-sphere model perturbed by a van d e r Waals attraction.
Review of Scientific Instruments, 1972
This paper presents a method for overcoming temperature and pressure limitations inherent in conv... more This paper presents a method for overcoming temperature and pressure limitations inherent in conventional techniques for measuring equilibrium thermodynamic data. The method can be applied to conducting materials that can be resistively heated and that do not dissociate in the liquid phase; and it is thus particularly suitable for investigating pure liquid‐metal thermodynamic data. The technique has been applied extensively to lead at temperatures exceeding 5000 K and at pressures up to 2 kilobars. A cylindrical material specimen 1 mm in diameter and 25 mm long is interposed between two current leads and mounted axially concentric with a high‐pressure cell. After the cell is pressurized with helium, a current pulse from the overdamped discharge of a high‐voltage capacitor bank heats the wire at such a rate that its expansion is nearly isobaric. The energy deposited in a central segment of the sample is computed by integrating the product of the current flowing in the segment with the resistive voltage dev...
Journal of Applied Physics, 1971
The dynamic yield strengths for several ceramics were measured under shock‐wave compression. The ... more The dynamic yield strengths for several ceramics were measured under shock‐wave compression. The Hugoniot elastic limit (HEL), taken as the amplitude of the observed elastic precursor traveling ahead of the compressional wave, was 154 and 82 kbar for B4C and BeO ceramics, respectively, and ranged from 61 to 134 kbar for several Al2O3 ceramics. These values apply to 6‐mm‐thick samples; in some cases there were variations with sample thickness. The offset of the Hugoniot from the isotropic compression curve in the stress‐volume plane indicates a nonzero yield strength above the HEL for Al2O3. This yield strength is somewhat less than the yield strength at the HEL. The compaction of porous ceramics is found to follow a quadratic variation with stress, full compaction being reached at about four times the HEL.
Journal of Applied Physics, 1970
The variation of shock‐induced phase‐transition pressure with alloy composition has been observed... more The variation of shock‐induced phase‐transition pressure with alloy composition has been observed for several Fe–Cr and Fe–Cr–Ni alloys through use of the inclined‐mirror technique. It was found that transition pressures for Fe–Cr alloys varied continuously from the known 130‐kbar value for pure iron to 230 kbar for 30% Cr content. Alloys of the Fe–Cr–8% Ni series exhibited almost linear decrease in transition pressure from 120 to 80 kbar as Cr was increased from zero to 18%; no transition was observed for an 8% Ni–22% Cr alloy up to 124‐kbar. Further systematic decreases in phase‐transition pressures were observed for Fe–Cr–12% Ni and Fe–Cr–16% Ni alloys.
Journal of Applied Physics, 1973
Dynamic yield strengths, compression data under uniaxial shock‐wave loading, and sonic velocities... more Dynamic yield strengths, compression data under uniaxial shock‐wave loading, and sonic velocities at 1 bar are reported for polycrystalline TiB2, SiC, Be4B, Be4B+8 wt% BeO, Be2B, AlB12, TiBe12, and ZrBe13. Hugoniot elastic limits were measured as 86, 80, 74, 77, 65, 87, 53, and 71 kbar, respectively. Evidence of phase transitions was seen for the Be4B materials at 500 kbar and for SiC at 240 and 960 kbar.
Journal of Applied Physics, 1972
... Axial yield strengths and phase-transition stresses for (100), (110), and (111) germanium* WH... more ... Axial yield strengths and phase-transition stresses for (100), (110), and (111) germanium* WHGust and EB Royce Lawrence Livermore Laboratory, University of California, Livermore, California 94550 (Received 5 June 1972) The dynamic compressive yield strengths and ...
Journal of Applied Physics, 1968
Measurements have been made of the shock‐induced reduction in the component of the magnetization ... more Measurements have been made of the shock‐induced reduction in the component of the magnetization of polycrystalline YIG along the direction of an applied field. This reduction is induced by the passage of an explosively generated shock wave in a direction perpendicular to the applied field. The data indicate that the passage of the shock wave through the sample induces a uniaxial magnetic anisotropy in the material. This magnetic anisotropy arises from the stress anisotropy associated with the shock‐wave compression of a material having a nonzero yield strength. The induced magnetic anisotropy makes the shock‐propagation direction an easy direction of magnetization, and the observed reduction in the component of the magnetization along the applied field arises mainly from the rotation of the magnetization toward the easy direction. Experiments were performed at three bias fields, each at three widely spaced shock pressures. At 0.09 Mbar, the induced anisotropy energy may be described by a term in sin2θ. T...
Journal of Applied Physics, 1971
... ROYCE Table III. Summary Al base plate pressure (kbar) Sound speed at 1 atm (mm/usec) Elastic... more ... ROYCE Table III. Summary Al base plate pressure (kbar) Sound speed at 1 atm (mm/usec) Elastic regime HE system Shock velocity, ил (mm//isec) Free sur-face veloc-ity, UfA (mm/jusec) Stress, (kbar) Volume, Vi (crnVg) Cl Cs A 99 8.30 5.79 8.30 0.865 83 0.4069 В 138 8.46 ...
Shock compression of the stainless uranium alloy mulberry (rho/sub 0/ = 16.4 g/cm/sup 3/) has bee... more Shock compression of the stainless uranium alloy mulberry (rho/sub 0/ = 16.4 g/cm/sup 3/) has been observed through use of inclined prisms. No Hugoniot elastic limit was apparent; both pressure and shock velocity (U/sub s/) rise continuously with compression. The propagation velocity rises slowly for values of particle velocity (U/sub p/) between 0 and 0.4 mm/..mu..s and then rises more rapidly. The equations for the line segments which approximate the (U/sub s/, U/sub p/) curve are U/sub s/ = 2.92 + 0.63U/sub p/ for U/sub p/ 0.4 mm/..mu..s.
Physical Review B
and Hf. It is deduced that only Ce exhibits phenomena that may be related to a 4f M electronic ph... more and Hf. It is deduced that only Ce exhibits phenomena that may be related to a 4f M electronic phase transition. An abrupt decrease in compressibility at at high pressure is taken to be evidence of the onset of interaction between closed electron shells in metals. This work is the first identification of the closed-shell electronic interactions in metals in a high-pressure experiment.
A three-phase equation of state for metals is developed, based on the following assumptions: (1) ... more A three-phase equation of state for metals is developed, based on the following assumptions: (1) t h e entropy of melting is independent of pressure; (2) the temperature dependence of the specific heat in the liquid is a universal curve, scaled on the melting temperature; (3) the p r e s s u r e dependence of the melting temperature is given by a modified Lindemam law; and (4) the liquid-vapor region may be described by a hard-sphere model perturbed by a van d e r Waals attraction.
Review of Scientific Instruments, 1972
This paper presents a method for overcoming temperature and pressure limitations inherent in conv... more This paper presents a method for overcoming temperature and pressure limitations inherent in conventional techniques for measuring equilibrium thermodynamic data. The method can be applied to conducting materials that can be resistively heated and that do not dissociate in the liquid phase; and it is thus particularly suitable for investigating pure liquid‐metal thermodynamic data. The technique has been applied extensively to lead at temperatures exceeding 5000 K and at pressures up to 2 kilobars. A cylindrical material specimen 1 mm in diameter and 25 mm long is interposed between two current leads and mounted axially concentric with a high‐pressure cell. After the cell is pressurized with helium, a current pulse from the overdamped discharge of a high‐voltage capacitor bank heats the wire at such a rate that its expansion is nearly isobaric. The energy deposited in a central segment of the sample is computed by integrating the product of the current flowing in the segment with the resistive voltage dev...
Journal of Applied Physics, 1971
The dynamic yield strengths for several ceramics were measured under shock‐wave compression. The ... more The dynamic yield strengths for several ceramics were measured under shock‐wave compression. The Hugoniot elastic limit (HEL), taken as the amplitude of the observed elastic precursor traveling ahead of the compressional wave, was 154 and 82 kbar for B4C and BeO ceramics, respectively, and ranged from 61 to 134 kbar for several Al2O3 ceramics. These values apply to 6‐mm‐thick samples; in some cases there were variations with sample thickness. The offset of the Hugoniot from the isotropic compression curve in the stress‐volume plane indicates a nonzero yield strength above the HEL for Al2O3. This yield strength is somewhat less than the yield strength at the HEL. The compaction of porous ceramics is found to follow a quadratic variation with stress, full compaction being reached at about four times the HEL.
Journal of Applied Physics, 1970
The variation of shock‐induced phase‐transition pressure with alloy composition has been observed... more The variation of shock‐induced phase‐transition pressure with alloy composition has been observed for several Fe–Cr and Fe–Cr–Ni alloys through use of the inclined‐mirror technique. It was found that transition pressures for Fe–Cr alloys varied continuously from the known 130‐kbar value for pure iron to 230 kbar for 30% Cr content. Alloys of the Fe–Cr–8% Ni series exhibited almost linear decrease in transition pressure from 120 to 80 kbar as Cr was increased from zero to 18%; no transition was observed for an 8% Ni–22% Cr alloy up to 124‐kbar. Further systematic decreases in phase‐transition pressures were observed for Fe–Cr–12% Ni and Fe–Cr–16% Ni alloys.
Journal of Applied Physics, 1973
Dynamic yield strengths, compression data under uniaxial shock‐wave loading, and sonic velocities... more Dynamic yield strengths, compression data under uniaxial shock‐wave loading, and sonic velocities at 1 bar are reported for polycrystalline TiB2, SiC, Be4B, Be4B+8 wt% BeO, Be2B, AlB12, TiBe12, and ZrBe13. Hugoniot elastic limits were measured as 86, 80, 74, 77, 65, 87, 53, and 71 kbar, respectively. Evidence of phase transitions was seen for the Be4B materials at 500 kbar and for SiC at 240 and 960 kbar.
Journal of Applied Physics, 1972
... Axial yield strengths and phase-transition stresses for (100), (110), and (111) germanium* WH... more ... Axial yield strengths and phase-transition stresses for (100), (110), and (111) germanium* WHGust and EB Royce Lawrence Livermore Laboratory, University of California, Livermore, California 94550 (Received 5 June 1972) The dynamic compressive yield strengths and ...
Journal of Applied Physics, 1968
Measurements have been made of the shock‐induced reduction in the component of the magnetization ... more Measurements have been made of the shock‐induced reduction in the component of the magnetization of polycrystalline YIG along the direction of an applied field. This reduction is induced by the passage of an explosively generated shock wave in a direction perpendicular to the applied field. The data indicate that the passage of the shock wave through the sample induces a uniaxial magnetic anisotropy in the material. This magnetic anisotropy arises from the stress anisotropy associated with the shock‐wave compression of a material having a nonzero yield strength. The induced magnetic anisotropy makes the shock‐propagation direction an easy direction of magnetization, and the observed reduction in the component of the magnetization along the applied field arises mainly from the rotation of the magnetization toward the easy direction. Experiments were performed at three bias fields, each at three widely spaced shock pressures. At 0.09 Mbar, the induced anisotropy energy may be described by a term in sin2θ. T...
Journal of Applied Physics, 1971
... ROYCE Table III. Summary Al base plate pressure (kbar) Sound speed at 1 atm (mm/usec) Elastic... more ... ROYCE Table III. Summary Al base plate pressure (kbar) Sound speed at 1 atm (mm/usec) Elastic regime HE system Shock velocity, ил (mm//isec) Free sur-face veloc-ity, UfA (mm/jusec) Stress, (kbar) Volume, Vi (crnVg) Cl Cs A 99 8.30 5.79 8.30 0.865 83 0.4069 В 138 8.46 ...