This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shea...This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shear localization, there is a direct relation between segmentation and alloy strength （hardness） that is related to the alloying elements and constitutive phases. For instance, alpha brass is successfully processed by ECAP at room temperature, but alpha/beta brasses fail even at a temperature of 350 °C. Finite element simulation of cracking and segmentation was performed using DEFORMTM to investigate the influence of different parameters on segmentation. The results confirm that friction and processing speed have narrow effects on attaining a perfect billet. However, employing back pressure could be reliably used to diminish shear localization, billet cracking, segmentation, and damage. Moreover, diminishing the flow localization using back pressure leads to uniform material flow and the billet homogeneity increases by 36.1%, when back pressure increases from 0 to 600 MPa.展开更多
Barium doped hafnium oxide nanoparticles were synthesized by an easy co-precipitation method. FTIR analysis and EDX investigation shows the purity and stoichiometric composition of hafnium oxide nanoparticles. XRD inv...Barium doped hafnium oxide nanoparticles were synthesized by an easy co-precipitation method. FTIR analysis and EDX investigation shows the purity and stoichiometric composition of hafnium oxide nanoparticles. XRD investigation exhibit the as syn-thesized nanoparticles are amorphous in nature and calcined barium doped hafnium oxide nanoparticles have the monoclinic phase structure with the mean crystallite size was around 15 nm. TEM analysis shows the development of crystalline Nano-rods. The Na-no-rod formations signify the possibility of its use in applications of sensor. Ultra violet visible spectroscopy investigation shows that the band gap of the nanoparticles is noticed between 5.4-5.14 eV. The visible and NIR of barium doped hafiniura oxide nanoparticles indicated high reflectance, which may possibly be employ as an antireflection coating in solar cells applications and high absorbance ultra violet region signify the viability of make use of the prepared nanoparticles could be used in Opto-electronic device applica-tions.展开更多
基金financial support and providing research facilities used in this work
文摘This research provides experimental evidence for localized shear, billet cracking, and segmentation during the processing of various copper alloys. The results demonstrate that although many parameters affect the shear localization, there is a direct relation between segmentation and alloy strength （hardness） that is related to the alloying elements and constitutive phases. For instance, alpha brass is successfully processed by ECAP at room temperature, but alpha/beta brasses fail even at a temperature of 350 °C. Finite element simulation of cracking and segmentation was performed using DEFORMTM to investigate the influence of different parameters on segmentation. The results confirm that friction and processing speed have narrow effects on attaining a perfect billet. However, employing back pressure could be reliably used to diminish shear localization, billet cracking, segmentation, and damage. Moreover, diminishing the flow localization using back pressure leads to uniform material flow and the billet homogeneity increases by 36.1%, when back pressure increases from 0 to 600 MPa.
文摘Barium doped hafnium oxide nanoparticles were synthesized by an easy co-precipitation method. FTIR analysis and EDX investigation shows the purity and stoichiometric composition of hafnium oxide nanoparticles. XRD investigation exhibit the as syn-thesized nanoparticles are amorphous in nature and calcined barium doped hafnium oxide nanoparticles have the monoclinic phase structure with the mean crystallite size was around 15 nm. TEM analysis shows the development of crystalline Nano-rods. The Na-no-rod formations signify the possibility of its use in applications of sensor. Ultra violet visible spectroscopy investigation shows that the band gap of the nanoparticles is noticed between 5.4-5.14 eV. The visible and NIR of barium doped hafiniura oxide nanoparticles indicated high reflectance, which may possibly be employ as an antireflection coating in solar cells applications and high absorbance ultra violet region signify the viability of make use of the prepared nanoparticles could be used in Opto-electronic device applica-tions.
