The factor responsible for formation of continuous chips in ductile material

Table of Contents • • • • • • • • • • • • • • Introduction: In the process of cutting metals in different shapes and sizes, there is a loss of material in the form of chips. Different cutting processes result in the production of different types of chips. In this article, we will discuss about the various types of chips that can be found while machining different materials. Contents • • • • • • • What is Chip in the Metal Cutting Process? In order to give metal a desired shape and size, extra metal is removed from the metal surface using various machine tools and techniques. This removed and deformed metal is called a Chip. Basic terminologies used during metal cutting: Rake face: It is the face of the cutting tool used. Rake angle: • It is the angle between the rake face and the normal to the machining surface. • A higher rake angle ensures better cutting and reduces cutting force as well. • But, it can be increased within a limit because it reduces the metal backup available at the tool rake and thus reducing the strength of the tooltip as well as heat dissipation through the tool. • It should be of the order 15 degrees and can be zero or negative when needed. Clearance Angle: • It is the angle between the underside of the tool (flank face) and machined surface. • Clearance angle is given so that tool doesn’t rub or spoil the metal surface. • It increases the cutting forces and is thus used of the order 5-6 degrees. • It is also called as relief angle. Chips Formation: •...

5. Conclusion The machining of metals highly depends on the types of chips it produces. When compared to the different production of metal, the metal is removed in various industries while doing the machining process is known as metal chips. You may wonder what is actually machining process stands for? In simple words, the In this process, the excess metal of the workpiece is removed in the form of chips. The types of chips formed in the machining process depend on some basic factors. In machining, the formation of chips is a necessary index because it indicates directly or indirectly the: • Nature and behavior of the material under the machining process. • Nature and degree of interaction in chip interfaces. • The amount of energy required to extract the material. Read also: What Are Some Conditions To Produce Chips? • Nature of material or workpiece • Material of • Level of decreasing velocity and feed rate • Machining environments like temperature • Cutting fluid • Dimension of tool • Friction between tool and work metal Types of Chips Types of chips in metal cutting are as follows: • Continuous chips • Discontinuous or segmented chips • Continuous chips with built-up edges 1. Continuous Chips In the machining process, continuous chips are formed during the machining of ductile material with high speed and minimum friction between the tool and material. Due to continuous plastic deformation by applying the tool, this type of chip is produced. Mild steel and copper is a ...

Material removed from a workpiece with the help of a tool are known as chips. Chips are formed by shearing. Machining of material is highly dependent on chips. Chips are formed during the machining process. As the cutting tool engages the workpiece, the material ahead of tool is sheared and deformed under tremendous pressure. The deformed material then seeks to relieve its stressed conditon by fracturing and flowing above the tool in the form of chip and hence the chips are formed. Machining can be a finishing or semi-finishing process done by removal of material from the workpiece. The excess material is removed from the workpiece in the form of chips. Some chips are also made for buiseness purpose. Coiled SS chips are sold for scrubbing and cleaning household vessels. Types of chip removed during a machining process depends on: 1) Material used as workpiece. 2) Material used in cutting tool. 3) Dimension of Tool. 4) Speed of cutting. 5) Feed Rate. 6) Cutting environment like temperature. 7) Friction between tool and workpiece. 8) Forces involved in metal cutting. The knowlwedge of chip type and when they are produced are very essential because it tells a lot about the condition of machining. Mainly chips are of three types :- 1) Discontinuous chips. 2) Continuous chips. 3) Continuous Chips with built up edges ( or BUE chips) These three types are elaborated below: 1) Discontinuous Chips:- If the chips during machining process is not continuous i.e. formed with breakage a...

Ductile mode cutting characteristics and material removal mechanism of brittle material are discussed using tungsten carbide as an example work material in this chapter. Grooving and milling tests are designed and conducted to investigate their cutting modes. Experimental results indicate that there is a transition from ductile mode cutting to brittle mode cutting in grooving of tungsten carbide when depth of cut is increased from zero to a certain value. SEM observations on machined work surfaces show that there are three cutting modes in grooving of brittle material as depth of cut being increased: ductile mode cutting, semi-brittle mode cutting and brittle mode cutting. Cutting modes is identified and classified by machined surface texture and chip formation. In ductile mode cutting of tungsten carbide, thrust force F t is much larger than cutting force F c, which results in a large compressive stress in cutting zone. Large compressive stress and shear stress could shield the growth of pre-existing flaws in work material by suppressing its stress intensity factor K I, such that K I< K C making work material is able to undertake a large cutting stress without fracturing to achieve ductile mode cutting. SEM and EDS examinations on cutting tools indicate that tool wear mainly occurs on flank face and tool wear mechanisms are dominated by diffusion, adhesion and abrasion in cutting of tungsten carbide. • Liu K (2002) Ductile cutting for rapid prototyping of tungsten carbide...

Chip Formation Chip formation involves a complicated interaction of plastic and elastic deformations within a small region, which is known as the shear zone. From: Comprehensive Materials Processing, 2014 Related terms: • Cutting Tool • Metal Matrix Composite • Plastic Deformation • Reinforced Plastic J.B. Mann, ... T.G. Murthy, in Nanostructured Metals and Alloys, 2011 7.4Bulk forms with ultrafine-grained (UFG) microstructure Chip formation by machining, as demonstrated in the above results for Cu, offers a means for producing nanostructured materials with controllable microstructures. While chips of macroscopic dimensions can be created by the unconstrained chip formation in machining, shape and size control of the chips would be advantageous and could complement the microstructure control earlier demonstrated. It is in this regard that the constrained chip formation process – LSEM (see Section 7.2.5) – offers capability for applying controlled SPD in the production of geometrically defined bulk forms, including sheet, foil and wire. 34 LSEM has been implemented in a rotary configuration for production of continuous foil 34 and in a linear configuration for production of sheet. 1 The linear configuration enables manufacture of larger-sized samples due to the increased load capacity of the press equipment used in this configuration. Additionally, a non-plane–strain rotary configuration has been used to produce nanostructured samples in wire and rod forms. Figure 7.11 show...