Materials and Process Classifications Chapter 2 Materials and Process Classifications

Objectives Differentiate between primary and secondary material processing industries. Major processing actions – forming, separating, conditioning, and finishing.

Manufactured Consumer Products There are 473 North American Industry Classification System (NAICS) product groups and approximately 1500 product classes. There are 5 major material families: metals, plastics, woods, ceramics, and composites. Most of the manufacturing activities conducted today involve the use of these materials. All manufacturing firms either: (1) make industrial stock from raw materials, (2) make new products from industrial stock, or (3) assemble parts into new products.

Raw Materials The online database MatWeb (www.matweb.com) lists data sheets for metals, plastics, ceramics and composite materials. Manufacturing processes are used by extractive industries – industries that collect raw material such as oil, gas, trees, and materials – to convert the basic raw material into refined material. These refined materials are then purchased as industrial stock and used to make finished products by hard goods manufacturing firms.

Major Material Families Major material families (fig 2-6, page 38) include: metallic, ceramics, plastics, woods, and composites. There are 94 different types of metal products manufacturing industries recognized by NAICS. Fig 2-10, page 39 indicates 10 significant industries. The American Ceramics Society (www.acers.org) classifies ceramics into 7 major industries (fig 2-8, page 39). Fig. 2-10, page 40 shows 10 major plastic industries. Poor judgment in selecting and using manufacturing processes will result in poor quality, lost time, and lost profits.

Process Action There are 5 major process actions: forming, separating, fabricating, conditioning, and finishing. Forming processes are used to change the size or shape of industrial stock. Bending, stretching, casting, pressing, and molding processes are all classified under the heading of forming. Separating processes are used to remove material or volume. Three different separating processes are: mechanical chip producing separating (example Sawing), mechanical non chip producing separating (example Shearing), and non mechanical separating (example Photochemical milling). Fabricating processes are those used to join and fasten materials together. Three major types of fabricating processes are : adhesion, cohesion, and mechanical joining. Soldering, brazing, and gluing are fabricating processes involving adhesion. Fusion welding and resistance welding are examples of cohesion. Conditioning processes often involve heat, shock, electrical impulses, magnetic methods, chemical action, or mechanical means to change the structural characteristics of the material. Conditioning processes are used to influence the hardness, strength, rigidity, resistance to wear, and fatigue (product life) of a material. Finishing processes are often used to improve the outward appearance or protect the exterior surface of a part.

Summary There are 5 major material families: metals, plastics, woods, ceramics, and composites. All manufacturing firms either: (1) make industrial stock from raw materials, (2) make new products from industrial stock, or (3) assemble parts into new products. There are 5 major process actions: forming, separating, fabricating, conditioning, and finishing. Forming processes are used to change the size or shape of industrial stock. Bending, stretching, casting, pressing, and molding processes are all classified under the heading of forming.

Home Work 1. What are the 5 major material families? 2. What are the 3 things that all manufacturing firms do? 3. What are the 5 major process actions? 4. Explain forming process with examples.