Materials Quality Control,Assurance and Selection

Dr. Emmanuel Kwesi Arthur

Email: ekarthur2005@yahoo.com

Phone #: +233541710532

Department of Materials Engineering,

Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

©2019

Course Code: MSE 456

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Lecture One

Goal and Objectives

Goals: This course is a required course in Metallurgical and Materials Engineering. The major goal is to provide an introduction to materials selection in relation to the design process. It also focuses on materials quality control and assurance.

There are several objectives for this course:

1.) To introduce the parameters that are important to design, to understand how they are interrelated, to understand how they relate to the materials selection process, and to use these concepts in engineering design.

2.) To develop the ability to use modern software (CES EduPack) in the materials selection and design process.

3.) To develop the ability to obtain materials property and processing data needed in the materials selection and design process from both handbooks and electronic sources.

4.) To provide an introduction to team-oriented projects that introduce basic approaches to product design and materials selection

5.) To introduce the common material quality control and assurance methods used in materials manufacturing industries.

Resources:

Text :

“Materials: engineering, science, processing and design” by M.F. Ashby, H.R. Shercliff and D. Cebon, Butterworth Heinemann, Oxford 2007, Chapters 1 and 2

“Materials Selection in Mechanical Design”, 4th edition by M.F. Ashby, Butterworth Heinemann, Oxford, 2006, Chapters 1 - 3.

Computer Software:

CES EduPack 2013 Design Software (grantadesign.com). We will be using this software throughout the semester. It can be used as a materials database, a processing database, and a materials selection tool. It will be installed on students’ computers for practice.

Syllabus: Attendance is your job – come to class!

Or our regularly scheduled time (Tues. 4:00-6:00 pm & Thurs. 8:00 – 9:00 am)

Homeworks

There will be homework in the form of problem sets and projects. The projects will focus on materials selection and design and will frequently include using the materials selection software, or library and web research.

The homework will typically be shorter assignments related to the material being covered in lecture.

Don’t copy from others; don’t plagiarize – its just the right thing to do!!

Tutorials – by Perseverance Dzikunu (TA)

Grading

Class Attendance, Pop Quizzes and Assignments – (5% of your grade!)

Mid Semester Exams – (15%) Group Project and Presentation (10%) End of Semester Exams (70%)

Homework: Homework problems will be uploaded on my website.Each student will turn in homework to the TA one week after itis assigned. On the day homework is due, students will berandomly selected to solve selected homework problems,explaining to the class how each problem is worked. Students areencouraged to work together on homework. Students will beevaluated on both the quality of their written answers and boardpresentations.

Design Presentation: The class will be divided evenly into groupsfor a materials selection in design projects. Projects for eachgroup will be assigned by the lecturer. Each group will write areport on their respective project, as well as make an oralpresentation to the class.

Exams: Exams will be based on homework and informationprovided in lecture, tutorials and assigned reading. All exams willbe closed book. The final will be cumulative. Relevant materialsselection charts, etc. will be provided.

1. Read the relevant material in the Ashby book (preferably before the lecture topic)

2. Review and understand the examples given in the book.

3. Do the assigned homework. If you are having difficulty with a particular concept, work additional problems given in the book on that topic that have the answers given in the back of the book.

4. Seek help: tutors, etc.

Academic success is directly proportional to the amount of time devoted to study.

Suggestions for success in this class:

Credits: 3 Credit Hours –Lecture

Prerequisite: No prerequisite, however, knowledge in strength of materials and core materials courses is plus.

Office Hours:I have an open door policy. If I am in my office, feel free to stop in and ask questions about the class or any other materials questions you may have. If you would like to meet at another time, please send me an email with several available times.

Academic Dishonesty: In general, academic dishonesty will not be tolerated. You will be practicing engineers in a few months. Integrity and competence are critical to your professional success. Developing bad habits in university will hinder your professional development and will weaken the prestige of your degree.

Design Stage

Unit Objective...

Introduce fundamental design concepts in

Materials Selection

You will learn about:

• design

• how structure dictates properties

• how processing can change structure

This unit will help you to:• use materials properly

• realize new design opportunities with materials

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MATERIALS SELECTION

Introduction

Materials selection is an important part of a larger process of creating new solutions to problems. This larger process is called ““Engineering Design””

Design of engineering components is limited by the available materials, and new designs are made possible by new materials

To see how important is the material selection in the design, consider the definition of ““engineering”” used by ABET in the U.S.A

According to Accreditation Board for Engineering and Technology (ABET), Engineering is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgement to develop ways to utilise

economically the materials and forces of nature for the benefit of mankind

Materials Selection

Materials Selection

Why Materials Selection

An incorrectly chosen material may lead not

only to part failure, but also unnecessary

life-cycle cost.

Selection of material is also related with

processing of material.

Hence, the designer must seek for the best

combination of design-material-process.

Functional Requirements

For satisfying the need, designer must determine essential and desirable features of the design.

They are expressed in the form of “functional requirements” concerning performance characteristics of materials (i.e. material properties).

As it is impossible to satisfy all requirements to the same degree, they are arranged in the order of importance to identify the areas of compromise.

Design Limitations Furthermore, a design must be in compliance with inevitable “design

limitations”.

Such requirements are expressed by means of 3M rule:

Manufacturing, Money, Maintenance

Manufacturing requirements are logically the first to be considered.

Hence, the designer must consider functional merits of the material as well as its , ability to be machined, shaped, formed, cast, welded, and so on.

Money (economic) requirements are based on the final product cost, which is

composed of raw material cost and production costs with overheads. The cost of any product should be as high as the customers can pay for it.

Finally, maintenance (service life) requirements will define whether replacement or repair is required. They depend upon size of the part, extent of possible damage, facilities of the customers, and the acceptable level of costs.

Failure of Materials

Failure happens when a design is no longer able to satisfy any of functional requirements.

Failures not only cause costly damage, but also may lead to loss of lives as in airplane crashes.

In most design problems, primary concern is to minimize the possibility of a premature failure in service. The service life can be in seconds (in case of space applications) or many years (in case of bridges) years (in case of bridges).

Possible failure modes during service are as follows:

Excessive deformation: yielding, buckling, stress rupture (creep)

Fracture: sudden brittle, fatigue (progressive), time dependent (creep)

Inordinate wear: abrasion

Deterioration: chemical (corrosion or oxidation), embrittlement (ductile to brittle transition), irradiation, natural (fungus, other growths)

In practice, it is impossible to predict failure mode of a part under severe service conditions.

Some failures happen soon after the part is in service, which are covered by a factor of safety.

However, time dependent failures are difficult or even impossible to avoid by applying factor of safety. In such cases, parts are withdrawn from service and tested for reliability. Such specific data are not found in general reference books.

Materials Selection

Classification of Engineering Materials

Machine Elements

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