Solution:

Joining processes:

Many products observed in day-to-day life, are commonly made by putting many parts together may be in the subassembly. For example, the ball pen consists of a body, refill, barrel, cap, and refill operating mechanism.

All these parts are put together to form the product as a pen. More than 800 parts are put together to make various subassemblies and the final assembly of a car or airplane.

A complete machine tool may also require assembly of more than 100 parts in various sub assemble or final assemblies. The process of putting the parts together to form the product, which performs the desired function, is called assembly.

An assemblage of parts may require some parts to be joined together using various joining processes. But assembly should not be confused with the joining process.

Most of the products cannot be manufactured as a single unit they are manufactured as different components using one or more of the above manufacturing processes and these components are assembled to get the desired product.

Joining processes are widely used in fabrication and assembly work. In this process, two or more pieces of metal parts are joined together to produce desired shape and size of the product.

The joining processes are carried out by fusing, pressing, rubbing, riveting, screwing, or any other means of assembling. These processes are used for assembling metal parts and in general fabrication work.

Such requirements usually occur when several pieces are to be joined together to fabricate a desired structure of products. These processes are used to develop steam or water-tight joints.

A temporary, semi-permanent, or permanent type of fastening to make a good joint is generally created by these processes. The temporary joining of components can be achieved by the use of nuts, screws, and bolts.

Adhesives are also used to make temporary joints. Some of the important and common joining processes are:

(1) Welding (plastic or fusion),

(2) Brazing,

(3) Soldering,

(4) Riveting,

(5) Screwing,

(6) Press fitting,

(7) Sintering,

(8) Adhesive bonding,

(9) Shrink fitting,

(10) Explosive welding,

(11) Diffusion welding,

(12) Keys and cotters joints,

(13) Coupling, and

(14) Nut and bolt joints.

Surface finishing processes:

Surface finishing processes are utilized for imparting the intended surface finish on the surface of a job. By imparting a surface finishing process, the dimension of the part is not changed functionally;

Either a very negligible amount of material is removed from a certain material is added to the surface of the job.

These processes should not be misunderstood as metal-removing processes in any case as they are primarily intended to provide a good surface finish or a decorative or protective coating on the metal surface.

The surface cleaning process is also called a surface finishing process. Some of the commonly used surface finishing processes are:

(1) Honing,

(2) Lapping,

(3) Superfinishing,

(4) Belt grinding,

(5) Polishing,

(6) Tumbling,

(7) Organic finishes,

(8) Sanding,

(9) deburring,

(10) Electroplating,

(11) Buffing,

(12) Metal spraying,

(13) Painting,

(14) Inorganic coating,

(15) Anodizing,

(16) Sheradising,

(17) Parkerizing,

(18) Galvanizing,

(19) Plastic coating,

(20) Metallic coating,

(21) Anodizing, and

(22) Sand blasting.

Processes Effecting Change in Properties:

Processes affecting change in properties are generally employed to provide certain specific properties to the metal workpieces for making them suitable for particular operations or use.

Some important material properties like hardening, softening and grain refinement are needed for jobs and hence are imparted by heat treatment. Heat treatments affect the physical properties and also make a marked change in the internal structure of the metal.

Similarly, the metal forming processes affect the physical properties of workpieces Similarly shot peening process, imparts fatigue resistance to workpieces.

A few such commonly used processes are given as under:

(1) Annealing,

(2) Normalising,

(3) Hardening,

(4) Case hardening,

(5) Flame hardening,

(6) Tempering,

(7) Shot peeing,

(8) Grain refining, and

(9) Age hardening.

In addition, some allied manufacturing activities are also required to produce the finished product such as measurement and assembly.