title: Additive manufacturing of Ti-6Al-4V with added boron: Microstructure and hardness modification

authors: Jackson, Benjamin Ivan

abstract: Titanium alloy composites with titanium boride (TiB) discontinuous reinforcement have shown improved performance in terms of strength, stiffness, and hardness. Producing this composite through selective laser melting (SLM) can combine the advantages of freeform design with the ability to produce TiB reinforcement in-situ. In this study, SLM was used to consolidate a pre-alloyed Ti-6Al-4V (Ti64) and amorphous boron (B) powder mixture with the intent of producing 1.5wt% TiB reinforcement in a Ti64 matrix. The processing parameters of laser power and scanning speed were investigated for their effect on the density, microstructures, and hardness of the composite material. The results showed that the boron and Ti64 composite could achieve a density greater than 99.4%. Furthermore, it was found that processing parameters changed the microstructural features of the material. The higher the energy density employed the more homogenous the distribution of boron modified material. Macro features were also observed with laser paths being clearly evident in the subsurface microstructure. Micro-hardness testing and density measurement also showed a corresponding increase with increasing energy density. Maximum hardness of 392.4HV was achieved in the composite compared to 354.2HV in SLM fabricated Ti64.

text: Additive manufacturing of Ti-6Al-4V with added boron: Microstructure and hardness modification Titanium alloy composites with titanium boride (TiB) discontinuous reinforcement have shown improved performance in terms of strength, stiffness, and hardness. Producing this composite through selective laser melting (SLM) can combine the advantages of freeform design with the ability to produce TiB reinforcement in-situ. In this study, SLM was used to consolidate a pre-alloyed Ti-6Al-4V (Ti64) and amorphous boron (B) powder mixture with the intent of producing 1.5wt% TiB reinforcement in a Ti64 matrix. The processing parameters of laser power and scanning speed were investigated for their effect on the density, microstructures, and hardness of the composite material. The results showed that the boron and Ti64 composite could achieve a density greater than 99.4%. Furthermore, it was found that processing parameters changed the microstructural features of the material. The higher the energy density employed the more homogenous the distribution of boron modified material. Macro features were also observed with laser paths being clearly evident in the subsurface microstructure. Micro-hardness testing and density measurement also showed a corresponding increase with increasing energy density. Maximum hardness of 392.4HV was achieved in the composite compared to 354.2HV in SLM fabricated Ti64.

year: 2018

title: An ecological perspective on ‘undisturbed’ lake catchments in the Rotorua District

authors: Shaw, William

abstract: There is currently concern about trends in water quality in some lakes in largely natural catchments. Various potential contributing causes are under consideration, including pest animals, such as wallabies, and pest plants. This presentation provides an overview of aspects of ecological history and processes at work in the catchments of selected lakes. By necessity, this is largely an historical analysis, but this provides important background for current trends, and also to understand landscape-level processes. The effects of potentially threatening influences, such as pest plants and animals, need to be evaluated within various contexts, including landscape history, ongoing geomorphological change, human disturbance, vegetation dynamics, and the relative contributions of natural and human-induced changes.

text: An ecological perspective on ‘undisturbed’ lake catchments in the Rotorua District There is currently concern about trends in water quality in some lakes in largely natural catchments. Various potential contributing causes are under consideration, including pest animals, such as wallabies, and pest plants. This presentation provides an overview of aspects of ecological history and processes at work in the catchments of selected lakes. By necessity, this is largely an historical analysis, but this provides important background for current trends, and also to understand landscape-level processes. The effects of potentially threatening influences, such as pest plants and animals, need to be evaluated within various contexts, including landscape history, ongoing geomorphological change, human disturbance, vegetation dynamics, and the relative contributions of natural and human-induced changes.

year: 2015

title: Eke panuku, eke tangaroa! How Black Ferns 7s athletes navigate Instagram and inspire the next generation in Aotearoa

authors: Keet, Thandiwe Maia

subjects: Gender

abstract: This thesis considers the role of Instagram in the lives of players on the New Zealand Black Ferns 7s rugby team, and audience engagement with players’ social media accounts. Using a mana wāhine methodology, this study explores how Black Ferns 7s players utilize and navigate Instagram, through mixed-methods enquiry, including a social media analysis of 8 players’ accounts, interviews with 3 Black Ferns 7s players, and talanoa sessions with members of the women’s rugby community in the Bay of Plenty, supplemented by input from Black Ferns players and fans via direct messages on Instagram. The quantitative social media analysis identified 4 key themes in players’ Instagram posts: achievement, team & rugby, life outside rugby, and culture & vulnerability. The analysis reveals that players post the most regarding their “team & rugby”, generating an “athlete first” self- representation. It finds a statistically significant difference in the thematic content of Instagram posts based on squad seniority and the number of followers a player has. Followers were found to engage most with posts regarding “achievement”, and the least with posts regarding “culture and vulnerability”.
The interviews elaborate upon these quantitative differences by highlighting why athletes specifically use Instagram, insights into Black Ferns aspirational team dynamics, and the importance of a player’s life outside of rugby. The thematic analysis also reveals the digital economic and collective labour involved in producing social media content as a member of this team, and what it means to be culturally “authentic” online in Aotearoa. It reveals the unique elements generated by the team-sport context of this study, including intra-team differences in social media usage. Furthermore, hauora, Indigenous role modeling, and Tall Poppy Syndrome emerge as factors particularly unique to the cultural context within which this study takes place. The discussions culminate in the establishment of a layered understanding of the external, internal, and individual factors which shape Instagram posting habits, and the features which most significantly impact why audiences follow the curated displays Black Ferns 7s athletes provide online.
This project contributes to international literature on sportswomen’s use of social media, demonstrating the powerful ways that players support one another in what, when, and how they post, and the importance of cultural identity in Māori and Pasifika players’ social media engagement. It further reveals the importance of team culture in shaping individual players’ social media and audience engagement. This thesis also highlights the significance of sporting and cultural histories and intersectional identities in digital self-representation and fan engagement with sportswomen’s social media usage.

text: Eke panuku, eke tangaroa! How Black Ferns 7s athletes navigate Instagram and inspire the next generation in Aotearoa This thesis considers the role of Instagram in the lives of players on the New Zealand Black Ferns 7s rugby team, and audience engagement with players’ social media accounts. Using a mana wāhine methodology, this study explores how Black Ferns 7s players utilize and navigate Instagram, through mixed-methods enquiry, including a social media analysis of 8 players’ accounts, interviews with 3 Black Ferns 7s players, and talanoa sessions with members of the women’s rugby community in the Bay of Plenty, supplemented by input from Black Ferns players and fans via direct messages on Instagram. The quantitative social media analysis identified 4 key themes in players’ Instagram posts: achievement, team & rugby, life outside rugby, and culture & vulnerability. The analysis reveals that players post the most regarding their “team & rugby”, generating an “athlete first” self- representation. It finds a statistically significant difference in the thematic content of Instagram posts based on squad seniority and the number of followers a player has. Followers were found to engage most with posts regarding “achievement”, and the least with posts regarding “culture and vulnerability”.
The interviews elaborate upon these quantitative differences by highlighting why athletes specifically use Instagram, insights into Black Ferns aspirational team dynamics, and the importance of a player’s life outside of rugby. The thematic analysis also reveals the digital economic and collective labour involved in producing social media content as a member of this team, and what it means to be culturally “authentic” online in Aotearoa. It reveals the unique elements generated by the team-sport context of this study, including intra-team differences in social media usage. Furthermore, hauora, Indigenous role modeling, and Tall Poppy Syndrome emerge as factors particularly unique to the cultural context within which this study takes place. The discussions culminate in the establishment of a layered understanding of the external, internal, and individual factors which shape Instagram posting habits, and the features which most significantly impact why audiences follow the curated displays Black Ferns 7s athletes provide online.
This project contributes to international literature on sportswomen’s use of social media, demonstrating the powerful ways that players support one another in what, when, and how they post, and the importance of cultural identity in Māori and Pasifika players’ social media engagement. It further reveals the importance of team culture in shaping individual players’ social media and audience engagement. This thesis also highlights the significance of sporting and cultural histories and intersectional identities in digital self-representation and fan engagement with sportswomen’s social media usage.

year: 2022