GSM: 08034843286; Email: phillip.babalola@covenantuniversity.edu.ng COURSE CODE: MCE314 COURSE TITLE: WORKSHOP PRACTICE(2 UNITS) COURSE COORDINATOR: DR. P.O. BABALOLA Engr. T.O Makun, Mr. Makinde Adisa, Mr. Olaniyi Kayode, Mr. Gbolahan Odewole, Mr. Siyanbola John., Mr. J.Oladotun GSM: 08034843286; Email: phillip.babalola@covenantuniversity.edu.ng

OBJECTIVES To prepare the students for various responsibilities they will bear as engineers and technologists in the industries, corporate bodies and other institutions even as individual entrepreneurs in the practice of engineering profession.

OBJECTIVES CONTD. To expose the students to all aspects of engineering workshop practice and other technical activities.   To train the students to translate the project designs into physical system and how to construct and refine prototypes.

WORKSHOPS IN MECHANICAL ENGINEERING *Machine shop *Foundry Workshop * Welding and Fabrication Workshop Automobile Workshop Refrigeration and Air Conditioning

PROGRAM OUTLINES (MECHANICAL) FOUNDRY SHOPS AND PROCESSES MECHANICAL WORKING OF METALS JOINING OF ENGINEERING MATERIALS SHEET METAL WORKS MACHINE SHOP

Specific Industries ©2010 John Wiley & Sons, Inc. M P

Manufacturing Industries - continued Secondary industries include manufacturing, construction, and electric power generation Manufacturing includes several industries e.g., apparel, beverages, chemicals, and food processing For our purposes, manufacturing means production of hardware Nuts and bolts, forgings, cars, airplanes, digital computers, plastic parts, and ceramic products ©2010 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 4/e

Manufactured Products Final products divide into two major classes: Consumer goods - products purchased directly by consumers Cars, clothes, TVs, tennis rackets Capital goods - those purchased by companies to produce goods and/or provide services Aircraft, computers, communication equipment, medical apparatus, trucks, machine tools, construction equipment

Materials in Manufacturing Most engineering materials can be classified into one of three basic categories: Metals Ceramics Polymers Their chemistries are different, and their mechanical and physical properties are different These differences affect the manufacturing processes that can be used to produce products from them

In Addition: Composites Nonhomogeneous mixtures of the other three basic types rather than a unique category Venn diagram of three basic material types plus composites

1. Metals Usually alloys, which are composed of two or more elements, at least one of which is metallic. Two basic groups: Ferrous metals - based on iron, comprises about 75% of metal tonnage in the world: Steel and cast iron Nonferrous metals - all other metallic elements and their alloys: Aluminum, copper, nickel, silver, tin, etc.

Charging a basic oxygen furnace in steelmaking: molten pig iron is poured into the BOF. Temperatures are around 1650C (3000F).

2. Ceramics Compounds containing metallic (or semi- metallic) and nonmetallic elements. Typical nonmetallic elements are oxygen, nitrogen, and carbon For processing, ceramics divide into: Crystalline ceramics – includes: Traditional ceramics, such as clay, and modern ceramics, such as alumina (Al2O3) Glasses – mostly based on silica (SiO2)

3. Polymers Compound formed of repeating structural units called mers, whose atoms share electrons to form very large molecules. Three categories: Thermoplastic polymers - can be subjected to multiple heating and cooling cycles without altering molecular structure Thermosetting polymers - molecules chemically transform into a rigid structure – cannot reheat Elastomers - shows significant elastic behavior

4. Composites Material consisting of two or more phases that are processed separately and then bonded together to achieve properties superior to its constituents Phase - homogeneous mass of material, such as grains of identical unit cell structure in a solid metal Usual structure consists of particles or fibers of one phase mixed in a second phase Properties depend on components, physical shapes of components, and the way they are combined to form the final material

Manufacturing Processes Two basic types: Processing operations - transform a work material from one state of completion to a more advanced state Operations that change the geometry, properties, or appearance of the starting material Assembly operations - join two or more components to create a new entity

Processing Operations Alters a material’s shape, physical properties, or appearance in order to add value Three categories of processing operations: Shaping operations - alter the geometry of the starting work material Property‑enhancing operations - improve physical properties without changing shape Surface processing operations - clean, treat, coat, or deposit material on surface of work

Shaping Processes – Four Categories Solidification processes - starting material is a heated liquid or semifluid Particulate processing - starting material consists of powders Deformation processes - starting material is a ductile solid (commonly metal) Material removal processes - starting material is a ductile or brittle solid

Solidification Processes Starting material is heated sufficiently to transform it into a liquid or highly plastic state Casting process at left and casting product at right

Particulate Processing (1) Starting materials are metal or ceramic powders, which are (2) pressed and (3) sintered

Deformation Processes Starting workpart is shaped by application of forces that exceed the yield strength of the material Examples: (a) forging and (b) extrusion

Material Removal Processes Excess material removed from the starting piece so what remains is the desired geometry Examples: (a) turning, (b) drilling, and (c) milling

MACHINING Metal chips fly in a high speed turning operation performed on a computer numerical control turning center (photo courtesy of Cincinnati Milacron).

Waste in Shaping Processes It is desirable to minimize waste in part shaping Material removal processes are wasteful in the unit operations, but molding and particulate processing operations waste little material Terminology for minimum waste processes: Net shape processes - little or no waste of the starting material and no machining is required Near net shape processes - when minimum machining is required

Property‑Enhancing Processes Processes that improve mechanical or physical properties of work material Examples: Heat treatment of metals and glasses Sintering of powdered metals and ceramics Part shape is not altered, except unintentionally Example: unintentional warping of a heat treated part

Surface Processing Operations Cleaning - chemical and mechanical processes to remove dirt, oil, and other surface contaminants Surface treatments - mechanical working such as sand blasting, and physical processes like diffusion Coating and thin film deposition - coating exterior surface of the workpart. Examples: Electroplating Physical vapor deposition Painting

Photomicrograph of the cross section of multiple coatings of titanium nitride and aluminum oxide on a cemented carbide substrate (photo courtesy of Kennametal Inc.).

Assembly Operations Two or more separate parts are joined to form a new entity Types of assembly operations: Joining processes – create a permanent joint Welding, brazing, soldering, adhesive bonding Mechanical assembly – fastening by mechanical methods Threaded fasteners (screws, bolts and nuts); press fitting, expansion fits

WELDING OPERATION Two welders perform arc welding on a large steel pipe section (photo courtesy of Lincoln Electric Company).

PROGRAM OUTLINES (MARKS) AUTOMOBILE WORKSHOP MACHINE SHOP WELDING AND METAL FABRICATION FOUNDRY WORKSHOP SAFETY 10 WORKSHOP TECHNIQUES 20 INDIVIDUAL REPORT GROUP PROJECT 40 INDIVIDUAL ATTENDANCE

TEXTBOOKS Grover M.P, Fundamentals of Modern Manufacturing, John Wiley & Sons, Inc, 2010 Introduction to Basic Manufacturing Processes and Workshop Rajender Singh Workshop Technology Vol. I & II. Gupta & Kaushik. Workshop Technology Vol. I & II. B. S. Raghuvanshi. Casting, John Campbell, Butterworth-Heinemann ©