title: Effect of spark plasma sintering temperature on microstructure and mechanical properties of an ultrafine grained TiAl intermetallic alloy

authors: Chen, Yuyong

subjects: spark plasma sintering

abstract: The effect of spark plasma sintering (SPS) temperature on the microstructure and mechanical properties of a bulk solid ultrafine grained gamma TiAl alloy produced by SPS of an ultrafine structured Ti/Al composite powder with a nominal composition of Ti–47 at.%Al has been investigated. The Ti/Al composite powder was produced using high energy mechanical milling. It was found that an SPS temperature of 800 °C led to the completion of the reactions needed for reaching the phase equilibrium and formation of a nanostructure with grain sizes in the range of 50–100 nm. However, this SPS temperature was not sufficient to achieve a nearly full density of the compact or a high level of interparticle bonding. Increasing the SPS temperature from 800 to 900 °C caused a significant increase of the density and the level of interparticle bonding while still maintaining grain sizes of <500 nm. The bulk TiAl alloy produced under this condition had a good compression yield strength, fracture strength, bending strength and plastic strain to fracture of 1722, 1963, 610 MPa and 4%, respectively. Increasing the SPS temperature from 900 to 1100 °C caused significant coarsening of the TiAl grains which led to a clear decrease in yield strength and hardness and a slight increase in ductility.

text: Effect of spark plasma sintering temperature on microstructure and mechanical properties of an ultrafine grained TiAl intermetallic alloy The effect of spark plasma sintering (SPS) temperature on the microstructure and mechanical properties of a bulk solid ultrafine grained gamma TiAl alloy produced by SPS of an ultrafine structured Ti/Al composite powder with a nominal composition of Ti–47 at.%Al has been investigated. The Ti/Al composite powder was produced using high energy mechanical milling. It was found that an SPS temperature of 800 °C led to the completion of the reactions needed for reaching the phase equilibrium and formation of a nanostructure with grain sizes in the range of 50–100 nm. However, this SPS temperature was not sufficient to achieve a nearly full density of the compact or a high level of interparticle bonding. Increasing the SPS temperature from 800 to 900 °C caused a significant increase of the density and the level of interparticle bonding while still maintaining grain sizes of <500 nm. The bulk TiAl alloy produced under this condition had a good compression yield strength, fracture strength, bending strength and plastic strain to fracture of 1722, 1963, 610 MPa and 4%, respectively. Increasing the SPS temperature from 900 to 1100 °C caused significant coarsening of the TiAl grains which led to a clear decrease in yield strength and hardness and a slight increase in ductility.

year: 2009

title: Do the right thing: Why we require sustainable business reports and what you can do about it.

authors: Martin, Kelly

subjects: corporation reports

abstract: The article focuses on the international initiatives that urge the use of sustainability business reports by organisations particularly corporations. It says that the United Nations (UN) joined with Ceres to create a Global Reporting Initiative (GRI) organisation that will help organisations use their sustainability performance information in reporting. It adds that the Accounting for Sustainability Forum (A4S) partnered with GRI to create the International Integrated Reporting Committee (IIRC).

text: Do the right thing: Why we require sustainable business reports and what you can do about it. The article focuses on the international initiatives that urge the use of sustainability business reports by organisations particularly corporations. It says that the United Nations (UN) joined with Ceres to create a Global Reporting Initiative (GRI) organisation that will help organisations use their sustainability performance information in reporting. It adds that the Accounting for Sustainability Forum (A4S) partnered with GRI to create the International Integrated Reporting Committee (IIRC).

year: 2011

title: Te hau mihi ata mātauranga Māori and science - Cross cultural dialogue

authors: Joseph, Robert

abstract: The Te Hau Mihi Ata Mātauranga Māori and Science research project (the research project) will explore ways to link mātauranga Māori and western science. The purpose of the research project is to open a new creative knowledge space to unleash innovative thinking and cross-cultural connection that is unique to New Zealand which can be a source of untapped economic, social, environmental and cultural potential. The historic marginalisation of alternative value and knowledge systems has prevented quality engagement and dialogue between these two knowledge systems in New Zealand. The research project will develop, inter alia, a new inter-cultural dialogue process between Māori educated in western-based science and experts in mātauranga Māori.

text: Te hau mihi ata mātauranga Māori and science - Cross cultural dialogue The Te Hau Mihi Ata Mātauranga Māori and Science research project (the research project) will explore ways to link mātauranga Māori and western science. The purpose of the research project is to open a new creative knowledge space to unleash innovative thinking and cross-cultural connection that is unique to New Zealand which can be a source of untapped economic, social, environmental and cultural potential. The historic marginalisation of alternative value and knowledge systems has prevented quality engagement and dialogue between these two knowledge systems in New Zealand. The research project will develop, inter alia, a new inter-cultural dialogue process between Māori educated in western-based science and experts in mātauranga Māori.

year: 2008-11