title: Comparison of the Cracking Behavior of Powder Metallurgy and Ingot Metallurgy Ti-5Al-5Mo-5V-3Cr Alloys during Hot Deformation

authors: Zhao, Qinyang

subjects: Science & Technology

abstract: The hot workability of metallic materials is significantly dependent on its ability to form plastic without cracking and fracturing. In this work, the cracking behavior of powder metallurgy (PM) Ti-5Al-5Mo-5V-3Cr (Ti-5553) alloy, consolidated from powder mixture, at a deformation temperature range of 600 ◦C–850 ◦C and strain rate of 0.1 s−1–10 s−1, was investigated through isothermal compression tests. The cracking behavior of the as-cast ingot metallurgy (IM) Ti-5553 alloy, at a deformation temperature of 700 ◦C was also investigated for comparison. Results suggested that the PM Ti-5553 alloy had a better hot workability, with a larger cracking-free processing window, and a lower deformation resistance than the IM counterpart. 45◦ shear fracture occurred in the PM alloy, compressed at the condition of 600 ◦C/10 s−1, and edge cracking was observed at the 700 ◦C/10 s−1. 45◦shear fracture was also significant in the IM alloy specimen tested at 700 ◦C/10 s−1, and all the other IM alloy specimens compressed at 700 ◦C displayed longitudinal cracking. Moreover, the microscopic cracking observation showed that ductile dimple cracking can be found in the IM alloy, but brittle cleavage fracture was dominant in the cracking surface of PM alloy with a relatively low cracking ductility

text: Comparison of the Cracking Behavior of Powder Metallurgy and Ingot Metallurgy Ti-5Al-5Mo-5V-3Cr Alloys during Hot Deformation The hot workability of metallic materials is significantly dependent on its ability to form plastic without cracking and fracturing. In this work, the cracking behavior of powder metallurgy (PM) Ti-5Al-5Mo-5V-3Cr (Ti-5553) alloy, consolidated from powder mixture, at a deformation temperature range of 600 ◦C–850 ◦C and strain rate of 0.1 s−1–10 s−1, was investigated through isothermal compression tests. The cracking behavior of the as-cast ingot metallurgy (IM) Ti-5553 alloy, at a deformation temperature of 700 ◦C was also investigated for comparison. Results suggested that the PM Ti-5553 alloy had a better hot workability, with a larger cracking-free processing window, and a lower deformation resistance than the IM counterpart. 45◦ shear fracture occurred in the PM alloy, compressed at the condition of 600 ◦C/10 s−1, and edge cracking was observed at the 700 ◦C/10 s−1. 45◦shear fracture was also significant in the IM alloy specimen tested at 700 ◦C/10 s−1, and all the other IM alloy specimens compressed at 700 ◦C displayed longitudinal cracking. Moreover, the microscopic cracking observation showed that ductile dimple cracking can be found in the IM alloy, but brittle cleavage fracture was dominant in the cracking surface of PM alloy with a relatively low cracking ductility

year: 2019-02-01

title: Keeping up with the 'digital natives': Integrating Web 2.0 technologies into classroom practice.

authors: Cleary, Alison

subjects: self-study

abstract: This report describes a self-study using an action research spiral of problem analysis, intervention design, trial, reflection and analysis. The main purpose of the study was to investigate and evaluate whether Web 2.0 technologies and, in particular, social software could be effectively integrated into a senior secondary English classroom.

The methodology used in the study, while mainly qualitative, did include a degree of quantitative data-gathering. The study took place over two terms of the 2007 school year in a semi-rural school south of Auckland. 

My Year 12 English class of twenty-four students were participants in the study and I was the teacher-researcher. As part of the study the students responded to my 'blog' and created and maintained their own 'blogs'. These 'voices' are important threads in this narrative. Two of my colleagues acted as 'critical friends' in this process.

During the study my own beliefs regarding new technology and the descriptor 'digital natives' were challenged. While the data collected and the interpretative analysis of it created further questions that need to be addressed, the findings indicate that there is a place for Web 2.0 technology and social software in English classrooms. The findings also show that in order for these applications to be integrated effectively, a number of issues need to be addressed. My recommendations as teacher-researcher at the 'chalk-face' attempting to keep up with the rapidly changing lives of our students concludes this report.

text: Keeping up with the 'digital natives': Integrating Web 2.0 technologies into classroom practice. This report describes a self-study using an action research spiral of problem analysis, intervention design, trial, reflection and analysis. The main purpose of the study was to investigate and evaluate whether Web 2.0 technologies and, in particular, social software could be effectively integrated into a senior secondary English classroom.

The methodology used in the study, while mainly qualitative, did include a degree of quantitative data-gathering. The study took place over two terms of the 2007 school year in a semi-rural school south of Auckland. 

My Year 12 English class of twenty-four students were participants in the study and I was the teacher-researcher. As part of the study the students responded to my 'blog' and created and maintained their own 'blogs'. These 'voices' are important threads in this narrative. Two of my colleagues acted as 'critical friends' in this process.

During the study my own beliefs regarding new technology and the descriptor 'digital natives' were challenged. While the data collected and the interpretative analysis of it created further questions that need to be addressed, the findings indicate that there is a place for Web 2.0 technology and social software in English classrooms. The findings also show that in order for these applications to be integrated effectively, a number of issues need to be addressed. My recommendations as teacher-researcher at the 'chalk-face' attempting to keep up with the rapidly changing lives of our students concludes this report.

year: 2008

title: Te whakatipu torekaihuruhuru hai ika-ā-Whiro

authors: Temara, Pou

subjects: Mana tūpuna

abstract: Kai roto i te mōteatea a Hone Tūwhare e mau ana ngā whakaaro me ngā kareāroto o tōku whakatipuranga o Tūhoe i te turakitanga a Mate i te tipua nei i a Te Rangihau i te tau 1987.  Mōwai ana te whenua, takarerewa ana te tangata. He atua te rite o Te Rangihau ki a Tūhoe. Ka kitea ia i ngā marae o Tūhoe, ka hikina te ngoi o te iwi, ka ora. Kua mate nei, tārū ana te iwi; kua hinga te rākau taumatua o ngā manu, kua hinga i te tao o te mate.

Kāore hoki i roa i muri mai o tōna wehenga atu ka whai muri ko tōna rēanga me tōna momo. Mā wai e ārahi te iwi? Mā wai e whakatika te waka ka tikoki, te iwi ka hē? Mā wai o tō mātau whakatipuranga e whakakīkī ngā whāruarua kua mahue mai nei i te ngaronga atu o tērā whakatipuranga taioreore? Koinei ngā mōhio o Tūhoe, he mana te kupu, he tapu te kōrero! Ahakoa i noho rātau ki te ako i a mātau mō te wā e ngaro ai tō rātau momo, tāupetia ana mātau e te mokemoke, he manu mahue i te kātua te rite. Ae, i reira anō ngā torekaihuruhuru e whakatore ana, engari kīhai i a rātau te mana tohunga o te rēanga ka ngaro.

text: Te whakatipu torekaihuruhuru hai ika-ā-Whiro Kai roto i te mōteatea a Hone Tūwhare e mau ana ngā whakaaro me ngā kareāroto o tōku whakatipuranga o Tūhoe i te turakitanga a Mate i te tipua nei i a Te Rangihau i te tau 1987.  Mōwai ana te whenua, takarerewa ana te tangata. He atua te rite o Te Rangihau ki a Tūhoe. Ka kitea ia i ngā marae o Tūhoe, ka hikina te ngoi o te iwi, ka ora. Kua mate nei, tārū ana te iwi; kua hinga te rākau taumatua o ngā manu, kua hinga i te tao o te mate.

Kāore hoki i roa i muri mai o tōna wehenga atu ka whai muri ko tōna rēanga me tōna momo. Mā wai e ārahi te iwi? Mā wai e whakatika te waka ka tikoki, te iwi ka hē? Mā wai o tō mātau whakatipuranga e whakakīkī ngā whāruarua kua mahue mai nei i te ngaronga atu o tērā whakatipuranga taioreore? Koinei ngā mōhio o Tūhoe, he mana te kupu, he tapu te kōrero! Ahakoa i noho rātau ki te ako i a mātau mō te wā e ngaro ai tō rātau momo, tāupetia ana mātau e te mokemoke, he manu mahue i te kātua te rite. Ae, i reira anō ngā torekaihuruhuru e whakatore ana, engari kīhai i a rātau te mana tohunga o te rēanga ka ngaro.

year: 2016