Principals Of Manufacturing Engineering PDF

PRINCIPALS OF MANUFACTURING ENGINEERING Basic Manufacturing Process  What is Manufacturing??  Manufacturing arrived from the Latin word “manu factus”, meaning “made by hand”.  Although modern manufacturing is accomplished by automated and computer-controlled machinery the word m...

PRINCIPALS OF MANUFACTURING ENGINEERING Basic Manufacturing Process  What is Manufacturing??  Manufacturing arrived from the Latin word “manu factus”, meaning “made by hand”.  Although modern manufacturing is accomplished by automated and computer-controlled machinery the word manufacturing is still in use.  Manufacturing is the process of converting raw materials into products.  MANUFACTURING Manufacturing can be defined in two ways; technologically and economically. In technology, manufacturing is the application of physical and chemical processes to alter the geometry, properties, and/or appearance of a starting material to make products. Manufacturing also includes assembly of multiple parts to make products. Manufacturing as a technical process  MANUFACTURING In economy, manufacturing is the transformation of materials into items of greater value by means of one or more processing and/or assembly operations. The key point is that manufacturing adds value to the material either by changing its shape or properties or by combining it with other materials that have been similarly altered. Manufacturing as an economic process  Manufacturing Products Manufacturing is important to our lives. Yet, we do not manufacture stuff just for the sake of manufacturing. We manufacture because we want to make money! Manufactured products: Final products by industries such as Aerospace, Automotive, Basic Metals, Computers, Electronics, Glass, Ceramics.  Manufacturing Capability A manufacturing plant consists of processes and systems (and people, of course) designed to transform a certain limited range of materials into products of increased value. Modern manufacturing consists of three main blocks; materials, processes, and systems. Manufacturing capability can be defined as the technical and physical limitations of a manufacturing firm and each of its plants. Dimensions of capability are: Technological Processing Capability, Physical Product Limitations and Production Capacity.  Materials in Manufacturing Most engineering materials can be classified into one of the three basic categories: (1) Metals, (2) Ceramics and (3) Polymers. They have different chemistries and their mechanical and physical properties are dissimilar. These differences affect the manufacturing processes that can be used to produce products from them. In addition, there are (4) Composites: nonhomogenious mixtures of the other three basic types rather than a unique category.  Materials in Manufacturing The relationship of the four groups is pictured in the following figure. Venn diagram of three basic material types plus composites.  Manufacturing Processes Manufacturing processes can be divided into two basic types: 1. Processing operations: transforms a work material from one state of completion to a more advanced state closer to the final desired product. It adds value by changing geometry, properties or appearance of the starting material. 2. Assembly operations: joins two or more components in order to create a new entity called an assembly, subassembly, etc. Classification of manufacturing processes  Manufacturing Processes Processing operations: use energy to alter a workpart’s shape, physical properties or appearance in order to add value to the material. There are three categories of processing operations: 1. Shaping operations: alter the geometry of the work material by methods including casting, forging and machining. 2. Property-enhancing operations: add value to the material by improving its physical properties without changing its shape; e.g. Heat treatment. 3. Surface processing operations: performed to clean, treat, coat or deposit material onto the exterior surface of the work. Examples for coating are plating and painting.  Manufacturing Processes Shaping processes: change the geometry of a work material by application of heat or mechanical force or a combination of both. It can be classified into four categories: 1. Solidification processes: the starting material is a heated liquid or semifluid that cools or solidifies to form the part geometry. 2. Particulate processing: the starting material is a powder, and the powders are formed and heated into the desired geometry. 3. Deformation processes: the starting material is a ductile solid that is deformed to shape the part. 4. Material removal processes: the starting material is a solid, from which material is removed so that the resulting part has the desired geometry.  Manufacturing Processes Solidification process: starting material is heated sufficiently to transform it to the liquid state. With the material (metals, plastics and ceramic glasses) in the liquid state, it can be poured into a mold cavity and allowed to solidify , thus taking a solid shape that is the same as the cavity. Figure 1.5 Casting (metals) and molding (plastics) processes.  Manufacturing Processes Particulate processing: Starting materials are powders of metals or ceramics. The powders are then pressed and sintered. The powders are first squeezed into a die cavity under a high pressure and then heated to bond the individual particles together. Figure 1.6 Particulate processing. (1) Starting material (2) Pressing and (3) Sintering.  Manufacturing Processes Deformation processes: the starting workpart is shaped by application of forces that exceed the yield strength of the material (material must be ductile enough (accomplished by means of heating)), this process includes extrusion and forging. Figure 1.7 Deformation processes (a) forging (b) extrusion  Manufacturing Processes Material removal processes: operations that remove excess material from the starting workpart to get the desired geometry. Most common processes in this category include machining and grinding. The former includes turning, drilling and milling. Other special processes are known as nontraditional processes as they use lasers, electron beams, electric discharge, etc. Figure 1.8 Material removal processes. (a) turning (b) drilling and (c) milling.  Manufacturing Processes Assembly operations: second basic type of manufacturing operations, in which two parts or more are joined permanently or semipermanently to form a new entity. - Permanent joining includes welding, soldering, adhesive bonding, etc. - Mechanical assembly fastens parts in a joint that can be conveniently disassembled (using threaded fasteners such as bolts, rivets, nuts, etc).  Manufacturing Processes Production machines and tooling: manufacturing operations are accomplished using machinery and tooling (and people of course). - Machine tools: power-driven machines used to operate cutting tools previously operated by hand. Used not only to make parts for consumer products, but also components for other production machines. The machine tool is the mother of all machinery. - Other production machines include presses for stamping operations, forge hammers for forging, rolling mills for rolling sheet steel, welding machines for welding, etc.  Manufacturing Processes Production equipment can be divided into two categories: - General purpose equipment: more flexible and adaptable for a variety of jobs. - Special purpose equipment: designed to produce a specific part in large quantities.  Production machinery usually requires tooling, which customizes the equipment for the particular part or product. Hence, the type of tooling depends on manufacturing process ).  Course Objectives Students should understand of the principles of the major manufacturing processes Students should be able to recognize the standard processes used to produce products Students should be able to select the optimal process to produce a product  Course Main Topics Introduction to Manufacturing Engineering. Materials in Manufacturing Metal Casting Metal forming Material Removal processes Material Joining processes Recent Developments in Manufacturing  Grading Term Work 20 % Quizzes and Assignments 5% Lab attendance, 5% Lab reports and 5% Lab exam 5% Midterm Exam 20% Final Exam 60%  Safety Comes First Safety Precautions 1. Dress Code: Students must come to the laboratory wearing a laboratory coat. Half pants, loosely hanging garments and slippers are not allowed. 2. To avoid injury, the student must take the permission of the laboratory staff before handling any equipment. 3. Students must ensure that their work areas are clean and dry to avoid slipping. 4. At the end of each experiment, students must clear off all tools and materials from the work area. 5. Careless handling of machines may result in serious injury. The equipment and materials used can be hazardous. Exercise care, use the available safety gear, and bring a lab coat. DO NOT OPERATE ANY EQUIPMENT IN THE ABSENCE OF THE ASSISTANT OR WORKSHOP TECHNICIAN!