Metal Forming Processes

UNIT – 3

METAL FORMING PROCESSES

Hot working and cold working of metals – Forging processes - Open, impression and closed die forging - forging operations. Rolling of metals - Types of Rolling - Flat strip rolling - shape rolling operations - Defects in rolled parts. Principle of rod and wire drawing - Tube drawing – Principles of Extrusion - Types - Hot and Cold extrusion.

INTRODUCTION

A product is produced by shaping the metal into the required shape and size. There are many methods such as casting, forming, joining and machining etc. to manufacture a product. The metal forming is one of the manufacturing methods. It is a widely used manufacturing method which finds applications in automotive, aerospace, defense and other industries. In this method, "no machining process" is carried out but it is used to achieve optimum mechanical properties in the metal.

Metal forming is a manufacturing process of obtaining the required shape and size on the raw material by applying forces on it. These forces may be tensile force, compressive force, bending or shear force or combinations of these forces. The stresses induced in the material are greater than yield stress and less than ultimate stress. The material experiences plastic deformation to change the shape of the component and converted to the desired shape of the component.

There are innumerable formed products such as cooking vessels, tooth paste containers, bicycle body, chains, tube fitting, fan blades etc. used in our daily life. The metal forming reduces the cavities present in the metal and also used to remove impurities. The wastage of material in metal forming process is negligible or too small. But the production is high when compared to other manufacturing processes.