In this article we will discuss about the processes used for joining metals. Learn about:- 1. Welding 2. Brazing 3. Soldering 4. Gas Cutting Process and Equipment or (Oxyacetylene Gas Cutting Process). 1. Welding: In olden days, in order to join two pieces of metals, riveting was done. But nowadays for joining two pieces of metals welding is done. So, [...]
In this article we will discuss about:- 1. Introduction to Solid Solution of Metals 2. Types of Solid Solutions 3. Hume Rothery's Rules for Primary Substitutional Solid Solubility. Introduction to Solid Solution: When the liquid solution of two metals crystallises, and if a solid of only single crystal structure forms, then a solid solution has formed. This happens when atoms [...]
Two main types of interstitial voids (between the bigger atoms) occupied by interstitial (small) solute atoms are: 1. Tetrahedral Voids 2. Octahedral Voids. When same sized spheres (hard balls) are packed in three dimensions, void spaces are present between the spheres. These voids are called interstitial voids. The size of the interstitial sites is always smaller than the common five [...]
In this article we will discuss about:- 1. Process of Crystallization of Pure Metals 2. Dendritic Solidification 3. Allotropy of Metals 4. Effect of Grain Size on Properties 5. Solid Solution 6. Intermediate Phases. Process of Crystallization of Pure Metals: A crystal may be visualised as forming from a centre of freezing, or nucleus, which is composed of a small [...]
The following points highlight the six main non-destructive tests conducted for identifying metals and alloys. The tests are: 1. X-Ray Radiography 2. Gamma Radiography 3. Magnetic Particle Inspection 4. Ultrasonic Testing 5. Electrical Method 6. Damping Test. 1. X-Ray Radiography: Radiography technique is based upon exposing the components to short wavelength radiations in the form of X-rays (wavelength less than [...]
The following points highlight the seven main tests conducted for identifying metals and alloys. 1. Tensile Test: The tensile test is one of the most widely used of the mechanical tests. There are many variations of this test to accommodate the widely differing character of materials such as metals, elastomers, plastics and glasses. The tensile test on a mild steel [...]
In this article we will discuss about the structure of metals and alloys. 1. Grain Structure: The microstructure of solid metallic bodies consists of grains. Grains consist of unit cells in which atoms are arranged in a particular order. The cell structure repeats itself throughout the volume of the grain (Fig. 1.1). That is why the grains are also called [...]
Ductility is an essential property of material for its formability. However, ductility is not something like absolute constant for a metal or alloy under all conditions. In fact, it gets modified by the process parameters that is why the same material may show different formability in different forming processes. Ductility is measured by the strain suffered by the material before [...]
In this article we will discuss about the mechanical properties and heat treatment of metals. Mechanical Properties of Metals: The properties of metals are defined as the characteristics of the metal which represent the quality of the metal and Heat treatment is the process of changing the mechanical properties of metals by controlling the heating and cooling rates. Properties of [...]
In this article we will discuss about:- 1. Effects of Carbon on Iron 2. Effect of Carbon on Mechanical Properties of Annealed Steels 3. Effect of Carbon Other Metals. Effects of Carbon on Iron: Of all the alloying elements, carbon exerts the most profound and significant effect on the allotropy of iron, as is illustrated in Fe-Fe3C diagram. The crystal [...]