Cold-working produces structural changes in polycrystalline metals and alloys, which can be broadly classified in three categories: 1. Changes in Shape and Size of Grains 2. Changes in Orientation of Grains 3. Changes in Internal Structure of the Grains. Category # 1. Changes in Shape and Size of Grains: Commercial metals and alloys are polycrystalline in nature in which the [...]
In this article we will discuss about:- 1. Meaning of Cold Working 2. Effects of Cold Working 3. Limitations. Meaning of Cold Working: Metal is said to be cold worked if it is mechanically processed below the recrystallization temperature of the metal. Most of cold working processes are performed at room temperature. Hot working usually results in the refinement of [...]
The following points highlight the cold working processes which are generally performed on metals. The cold working processes are: 1. Shearing Operations 2. Drawing 3. Squeezing Operations 4. Bending Operations. 1. Shearing Operations: i. Blanking: This is the operation carried out on presses and consists of cutting the outside contour of a stamping. Production of sheet-metal blanks of flat shapes [...]
In this article we will discuss about the meaning and benefits of flex forming of metals. Meaning of Flex-Forming: High pressure sheet metal forming with flexible tools process, called as flex-forming is widely used in the aero-space and automotive industries, as well as in other industries where sheet metal parts are produced. Parts with complex shapes can be flexing formed. This [...]
Bending of pipe, tube, or extruded shapes involves practices and theories of the simple supported beam, the cantilever beam, and many of the problems of forming and deep drawing. Although the theories may become quite complete, the concept of tension stresses in the outside of the bend and compression of the inside surface is common to all bending, regardless of [...]
Fig. 6.48 shows a four-axis Multicut NC Centre used for carrying out all types of cold working operations in a single set up. Setting-Up: 4 axis MCNC control; take-up position can be selected as required; variable inlet chamber size; maximum travel speed 1600 mm/sec; simultaneous travel on max. 3 axes; computer controlled deposit position; longitudinal and transverse division by robot. [...]
The first step in designing for bending is the choice of material and its physical size and shape, for all other considerations will be directly related. In many cases, the type of material is governed by the end use of the part, such as structural high temperature and pressure applications, corrosion resistance, weight or for food and dairy applications. Perhaps [...]
In this article we will discuss about:- 1. Meaning of Deep Cryogenic Process 2. Advantages of Cryo Treated Tools 3. Cryogenics Technology for Quality Improvement and Cost Reduction 4. Metallurgy and Mechanics. Meaning of Deep Cryogenic Process: Deep Cryogenic process is a process of cold (dry thermal) treatment at - 185°C. It is controlled very precisely. It is used in [...]