CHAPTER MENU
1.1 The World’s Kitchens – The Innovation Centers for Materials Development 1.1.1 Defining High Temperature Based on Cracking Characteristics
1.2 Trinities of Earth’s Structure and Cryosphere 1.2.1 Trinity of Earth’s Structure 1.2.2 Trinity of Earth’s Cryospheric Regions
1.3 Earth’s Natural Materials (Rocks and Ice) 1.3.1 Ice: A High-Temperature Material 1.3.2 Ice: An Analog to Understand High-Temperature Properties of Solids
1.4 Rationalization of Temperature: Low and High
1.5 Deglaciation and Earth’s Response
1.6 High-Temperature Deformation: Time Dependency 1.6.1 Issues with Terminology: Elastic, Plastic, and Viscous Deformation 1.6.2 Elastic, Delayed Elastic, and Viscous Deformation
1.8 Paradigm Shifts 1.8.1 Paradigm Shift in Experimental Approach 1.8.2 Breaking Tradition for Creep Testing 1.8.3 Exemplification of the Novel Approach 1.8.4 Romanticism for a Constant-Structure Creep Test References
1.1 The World's Kitchens – The Innovation Centers for Materials Development
Engineering development is intricately linked with our understanding and manipulation of various kinds of materials, which are either readily available on land and sea or fabricated from them. Long before the dawn of civilization, Earth's surface had gone through many cycles of freezing and thawing. The ice age and deglacierization or melting of glaciers and ice sheets, still persisting on Earth's surface, played a pivoting role in shaping our lives and materials development. There is no question that ice played an important role in shaping the land and making adjustments in living conditions. But what does ice have to do with a book like this, entitled Engineering Physics of High‐Temperature Materials? In this book, we demonstrate how the knowledge of the physics of ice – a material that exists close to its melting point – can improve our understanding of all high‐temperature engineering materials. However, let us first explore a bit of human history and development in the usage of building materials.
The “Stone Age,” an archeological term of the three‐age system, was characterized by the use of stone as implements and ended variably between about 9000 and 2000 BCE in different areas of the world with the development of metalworking. It has been divided into the Paleolithic, Mesolithic, and Neolithic periods (Bates and Jackson 1980). The “Bronze Age,” characterized by metalworking and primarily the alloying of copper with tin and arsenic, took over between roughly 3000 and 1000 BCE with the “Iron Age” starting roughly between 1200 and 600 BCE.
The advent of the current cycle of global warming, which roughly began around 18 000 years ago (estimated peak period of the last glaciation), led humans as well as other species to move into areas previously covered with ice. A straightforward, easy‐to‐read introduction to various aspects of geology, which is useful to materials scientists and engineers who are not familiar with geological science, can be found in Physical Geology (Plummer and McGeary 1985). The process of deglaciation took a long time. The bulk of the ice sheets on Earth's surface melted away around 10 000 years ago. The global sea level was at its lowest level during the peak period of the last ice age, but it started to rise as the meltwater returned to the oceans. However, as ice melted, the ice load on the glaciated land, floating on Earth's molten mantle, decreased and the land areas started to rebound rapidly in the beginning and then slowed down. Most of the global land areas being used today, including those far away from the previously glaciated areas, became available about 6000 years ago, with one well‐documented exception of the loss of land – Australia's Great Barrier Reef (GBR). The 2400 km long GBR did not exist 15 000 years ago.
We may safely say that materials development accelerated from the middle of the current period of geologic time, which is known as the “Holocene Epoch” that started around 12 000 years ago. The Holocene (meaning wholly or entirely new) period began at the close of the Paleolithic Ice Age. Here, the “Age” (geochrone) is understood as the time interval during which a particular event occurred or a time characterized by unusual physical conditions, which is one of the many definitions used for describing a unit of geologic time (Bates and Jackson 1980; Lapidus 1987).
Trinity of Fire
PRODUCTION
CONTROL
MAINTENANCE
In the early Holocene age, the primary human needs arose from requiring protection from the elements and broadening food sources. These necessities led to the quest for controlled fire and with it the realization of the need for techniques for producing (P) and controlling (C) fire at will, rather than depending on its natural sources, as well as maintaining (M) fire as the need arose.
The trinity of fire (PCM) – i.e. generating fire whenever the need arises, using it, and preserving the source – was probably the most important aspect of human development. PCM provided hominines with the opportunity to extend their habitats to colder regions of the earth where caves could be used as heated (air‐conditioned!) and protected shelters. It also started a new era – the taste for cooked food and the beginnings of the kitchen for such food items anywhere, any time. The concept of “home cooking” and the advent of kitchens, marked, albeit debatable, the departure point from the cohabiting animal, although many animals and birds have developed the taste for burnt food produced during natural fires in forests or grassy lands.
Producing fire under dry environmental conditions was perhaps the beginning of this phase of human development and that of “kitchen” and “home cooking.” PCM heralded a transition from nomadic, constantly moving communities of hunters and gatherers and cave dwellers, to relatively stable societies with fabricated housing, making tools for various applications, and eventually to the development of agriculture and thus creating new social structures, to name a few.
Trinity of Civilization
TECHNOLOGY
FIRE
LANGUAGE
No doubt, PCM was responsible for opening an unlimited number of opportunities for the development of wide‐ranging technologies.