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| Name | AMIE Exam Lectures- Material Science and Engineering | Diffusion in Solids | Affecting Factors | 5.3 |
| Video Uploader | Video From Edupedia World by Exambyte |
| Upload Date | This Video Uploaded At 31-03-2017 12:47:53 |
| Video Discription | Engineering Subjects: Introduction to Material Science and Engineering: Material Science and Engineering | Diffusion in Solids | Factors Affecting Diffusion | 5.3 Review: In the last couple of videos, we have been discussing, about diffusion processes. So far we have discussed • What diffusion is? • How diffusion takes place even in solid • Different types of Diffusion • Different Diffusion Mechanism • The fundamentals of Diffusion • What they steady state and non-steady state diffusions In this lecture, we shall discuss further, about diffusion and see what are the factors affecting the rate of Diffusion or we can say what are the factors that determine how fast diffusion takes place. What are the factors affecting Diffusion? 00:00:30 1. Diffusion Species – The material in which the diffusion is taking place and the atom which we are talking about Mechanism – What is the mechanism, whether it is Vacancy Diffusion, Interstitial Diffusion, the size of the atom and so on 2. Temperature – How the temperature is going to be affecting 3. Alternative Diffusion Paths – In addition to the traditional paths like Vacancy and Interstitial paths there are some alternative paths which help in diffusion Diffusing Species & Diffusion Mechanism – 00:01:31 • The Diffusion Coefficient (D) depends on the diffusing species and the mechanism followed for diffusion. J depends on D for diffusion and D depends on what is the diffusing species and what mechanism is followed for diffusion. • Smaller atoms diffuse easily for obvious reasons • Interstitial Diffusion is easier than Self Diffusion • An example to highlight that different mechanism has a different rate of diffusion. Temperature – 00:04:12 • The most important factor the rate of diffusion is the temperature. • Diffusing Mechanism is not under our control. The species and the mechanism are fixed. But the temperature can be altered and it is controlled by the user. • Temperature affects the Diffusion Coefficient (D) directly and the increase is exponential. • Higher the value of T, higher would be the value of D and the diffusion will be much faster. • So the diffusion rate will be higher with high temperature. Alternative Paths of Diffusion – 00:06:46 • Regions of imperfections provide an easier path for Diffusion. • Defects such as dislocations, grain boundary and external surfaces provide a much faster path for atomic movement, as they are regions of high energy. • These provide the path for easy diffusion. • Faster than bulk diffusion. • Effective contribution is far smaller than the bulk diffusion. To Sum up – 00:08:17 • There are several factors affecting diffusion including the species in which the diffusion is going to take place and the mechanism that would follow, but we do not have much control over these. • Then we have the alternative paths such as the defects like dislocations, grain boundary and external surfaces but their contribution is far smaller than the bulk diffusion. • Then most importantly the temperature factor, which is much under our control and which has an exponential effect on the rate of diffusion. - In the last 3 lectures, we have seen and understood the process of diffusion in solid materials. - This will help in understanding the fundamental of Material Science much better with different processing mechanisms and different metal working process that takes place in metallurgy, which has a lot to do with diffusion and different heat treatments. In the next video, we shall start a new topic, where we will see the different mechanical test and examinations that we can take for a material to see its different properties. A video by Edupedia World (www.edupediaworld.com), free online education Click here for more videos on this topic: https://www..com/playlist?list=PLJumA3phskPFPkGEkQe6YWZs8Z1-9xkkg All Rights Reserved. [zTVe644B4Ms] |
| Category | Education |
| Tags | Diffusion | Diffusion in Solids | Vacancy Diffusion | Interstitial Diffusion | Engineering | Introduction to Material Science and Engineering | Types of Diffusion | Diffusion Mechanism | What is Diffusion | Self Diffusion | Impurity Diffusion | Inter Diffusion | How diffusion takes place | Material Science and Engineering | Free Learning materials | Factors Affecting Diffusion | Diffusion Coefficient | Free Engineering Study Materials | amie exam | amie 2017 | amie syllabus | edupedia world |
