Results for 'titan'

Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding

The achievement of high-efficiency and precise grinding of difficult-to-cut metals-like titanium alloys-is essential in the aerospace industry. However, the process often results in thermal damage to the workpiece surface, posing a significant technical challenge. While minimum quantity lubrication (MQL) has been used to aid titanium alloy grinding, its effectiveness is limited by insufficient heat dissipation and lubrication. As an alternative to normal temperature air for carrying micro-lubricants, Cryogenic air has shown promise in improving oil film heat transfer and lubrication performance in the grinding zone, thus reducing workpiece surface thermal damage. The experimental state of the technology demands more comprehensive studies on its effectiveness and on the underlying mechanisms. Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding addresses these challenges by providing a theoretical framework for understanding and optimizing cryogenic air minimum quantity lubrication in grinding processes, particularly for titanium alloys. It explores the physical characteristics of lubricants under cryogenic conditions, the influence of low temperatures on atomization effects, droplet formation dynamics, and heat transfer mechanisms within the grinding zone. By establishing quantitative relationships between cryogenic air parameters and lubricant properties, the book lays a foundation for enhancing the cooling lubrication mechanism of cryogenic air MQL in grinding processes. Researchers, scholars, and graduate students in universities and research institutes focusing on machining will find this book invaluable, as it goes beyond the theoretical insights into practical solutions to enhance grinding efficiency and reduce thermal damage.

Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding

The achievement of high-efficiency and precise grinding of difficult-to-cut metals-like titanium alloys-is essential in the aerospace industry. However, the process often results in thermal damage to the workpiece surface, posing a significant technical challenge. While minimum quantity lubrication (MQL) has been used to aid titanium alloy grinding, its effectiveness is limited by insufficient heat dissipation and lubrication. As an alternative to normal temperature air for carrying micro-lubricants, Cryogenic air has shown promise in improving oil film heat transfer and lubrication performance in the grinding zone, thus reducing workpiece surface thermal damage. The experimental state of the technology demands more comprehensive studies on its effectiveness and on the underlying mechanisms. Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding addresses these challenges by providing a theoretical framework for understanding and optimizing cryogenic air minimum quantity lubrication in grinding processes, particularly for titanium alloys. It explores the physical characteristics of lubricants under cryogenic conditions, the influence of low temperatures on atomization effects, droplet formation dynamics, and heat transfer mechanisms within the grinding zone. By establishing quantitative relationships between cryogenic air parameters and lubricant properties, the book lays a foundation for enhancing the cooling lubrication mechanism of cryogenic air MQL in grinding processes. Researchers, scholars, and graduate students in universities and research institutes focusing on machining will find this book invaluable, as it goes beyond the theoretical insights into practical solutions to enhance grinding efficiency and reduce thermal damage.

21st Century Nanoscience – A Handbook

This up-to-date reference is the most comprehensive summary of the field of nanoscience and its applications. It begins with fundamental properties at the nanoscale and then goes well beyond into the practical aspects of the design, synthesis, and use of nanomaterials in various industries.

1. René , Faust

Quarzkristall-Mikrowaagen-Studie zum Wachstumsverhalten alternierend gewachsener Schichten aus Titandioxid und Aluminiumoxid

Masterarbeit aus dem Jahr 2015 im Fachbereich Chemie - Sonstiges, Note: 1,0, Universität Hamburg, Sprache: Deutsch, Abstract: In dieser Arbeit wurde mittels einer in dieser Arbeitsgruppe erstmals aufgebauten und optimierten, ultra-genauen Quarzkristall-Mikrowaage das initiale Wachstum von TiO2 auf Al2O3 (1), und umgekehrt von Al2O3 auf TiO2 (2) untersucht. Im Fall (1) wurde ein verstärktes WPZ beobachtet, welches an das WPZ für das Wachstum von Al2O3 auf sich selbst angeglichen war. Umgekehrt war im Fall (2) das Wachstum von Al2O3 auf TiO2 stark inhibiert, und an das WPZ für das Wachstum von TiO2 auf sich selbst angeglichen. Kontrolluntersuchungen lassen in beiden Fällen eine intrinsische Inhibition des TiO2-Prozesses als Ursache vermuten.Weiter wurde zur Untersuchung des initialen Wachstums ein neuer Ansatz zur Auswertung der Daten entwickelt. Das WPZ wurde als eine Funktion der Massenbelegung aufgetragen. Es zeigt sich, dass das WPZ bis zum Erreichen des Massenäquivalents einer Monolage exponentiell auf den Wert des WPZ in Sättigung fällt. Zur Erklärung dieser Beobachtung wurde ein einfaches Modell entwickelt.In der Atomlagenabscheidung kommt dem initialen Wachstum eine besondere Bedeutung zu. Die Geschwindigkeit des Wachstums wird durch das Wachstum pro Zyklus (WPZ) quantifiziert. Das initiale WPZ kann von dem für ein Materialsystem angegebenen Literaturwert abweichen, da dort häufig das WPZ gemittelt über mehrere hundert Zyklen angegeben wird. Dagegen ist das initiale WPZ zunächst noch von den Eigenschaften des Substrats abhängig. Es kann inhibiert oder verstärkt sein.Praktische Bedeutung hat dies insbesondere bei Prozessen mit Superzyklen und Nanolaminaten. Hier werden einzelne Zyklen des Wirtsmaterials, z.B. Titandioxid (TiO2), durch solche zur Darstellung von z.B. Aluminiumoxid (Al2O3) ersetzt, um das Wirtsmaterial mit Al3+-Ionen zu durchsetzen. Für eine gezielte Dosierung ist die Kenntnis des initialen WPZ entscheidend.

1. Glen Andrew , Porter
2. Rwei Ching , Chang
3. Ching Kong , Chao

Characteristics and Thermal Behavior of Sputtered Titanium Thin Films on Various Substrates

Titanium films are growing in popularity, and are soon expected to replace copper for metallization purposes. However, the thermal stress behavior of titanium films had not been extensively studied, and therefore not clearly understood. Thus, the main goal of this work was to develop a systematic process to analyze and model the d¿/dT evolution between 20ºC and 300ºC, in sputtered, titanium thin films. A biaxial stress state has been legitimately assumed. In the laboratory, titanium films, with a nominal thickness of 200 nm, were deposited on five different kinds of unheated substrates, by RF magnetron sputtering. These substrates included titanium plate, soda-lime glass and three kinds of p-type silicon wafers, having crystallographic orientations of (100), (110) and (111). X-ray diffraction was used to characterize the crystallographic evolution with respect to temperature. By utilizing a heating chamber and special tooling, the lattice spacings were measured in-situ, and the thermal stress behaviors were estimated with either the sin2¿ method or the d-spacing method.

Electrochemically Engineered Nanoporous Materials

This book provides in-depth knowledge about the fabrications, structures, properties and applications of three outstanding electrochemically engineered nanoporous materials including porous silicon, nanoporous alumina and nanotubular titania.