Properties and Application of Engineering Materials

Running Head: PROPERTIES AND APPLICATION OF ENGINEERING MATERIALS 1
: PROPERTIES AND APPLICATION OF ENGINEERING MATERIALS
Name
University

PROPERTIES AND APPLICATION OF ENGINEERING MATERIALS 2
Task one: Introduction
A Mountain bicycle is designed to handle the roughest terrain while maintaining the
highest level of performance. The bike needs to handle single tracks, fire roads, and other
unpaved surfaces. The ground is mostly occupied with rocks, loose gravel, steep gradients, and
muddy areas (Brongersma, Halas, & Nordlander, 2015). The Manufacture and performance of a
new model of a bicycle depend majorly on the engineering materials selected. The new product
has to meet low production cost and aesthetic expectations of a customer (Smith & Suzuki,
2018). The engineering materials present today which can be used in the bicycle development
are metals, polymers, ceramics, composites and smart materials (Ashby, 2012). Minerals are a
group of engineering materials which are opaque and lustrous. They are good conductors of heat
and electricity. Polymers consist of a class of natural or synthetic substances made up of large
repeating chains of molecules. The next level of materials is known as ceramics which includes
an inorganic compound of metal and a non-metal held by both ionic and covalent bonds.
Composites, on the other hand, constitute two or more materials combined with a material with
different characteristics from individual elements (Aguilar, 2019). Lastly, smart materials
possess one or more properties which can be significantly changed in a controlled manner by
external stimuli.
Task two: Development of the bicycle frame and gear set
I. bicycle frame
A bicycle frame is made to have maximum stiffness and performance (Ashby, 2012). The
structure accommodates both axial and torsional loads which are experienced in cycling. The
structure must be strong to support the own rider weight without compromising the bicycle’s

PROPERTIES AND APPLICATION OF ENGINEERING MATERIALS 3
performance. During operation, the bicycle frame is subjected to tear and wear (Callister, 2007).
The structure has to be light enough and comfortable to the rider. The main frame components
include front fork, seat post, headset, and bottom bracket. Some materials can be used in
attaining the best capabilities of the bicycle frame, or a single element can be selected. The
excellent article (s) will enable the bicycle to operate under extreme conditions efficiently and
pose little or no manufacturing challenge. The conventional materials used in the manufacture of
the frame are metals or their alloys, composites, and thermoplastics.
Metals
Metals which are used in frame manufacture include aluminum, steel, titanium, and
magnesium. Metals have a good machinability capability which is economical in terms of low
production cost. Metals also have a high modulus of elasticity and show adequate stiffness of
within a huge load span. Metals have high strength of up to 1600 mega Pascal (Mpa) (Ashby,
2012). Corrosion can be controlled easily in metals by coating the metal surface. The mode of
joining in metals is by use of mechanical fasteners, welding and riveting. Also, metals are not
affected by the conversion process except in solder where local heat affected zones (has) occur
due to local heating. During machining of metals, little or no change occurs to the metal structure
hence retaining the original characteristics. Metals have high densities making them not suitable
material for the frame. During the operation period frames made of metals retain their properties
for an extended period. Rework, and maintenance of structures built of metals is easy. Quality
inspection in metals is easy. Nondestructive tests Methods which are used to inspect the metals
are magnetic particle testing, ultrasound and electromagnetic testing make testing of metal
products easy (Callister, 2007).

PROPERTIES AND APPLICATION OF ENGINEERING MATERIALS 4
Composites
The most common composite used in structure development is carbon fiber. It offers the
advantage of low weight, stiffness, and durability (Joshi, 2017). Carbon fiber body frame can
handle torsional and axial loads efficiently due to its high fiber stiffness. Carbon fiber saves on
the production cost because it does not need secondary manufacturing processes like polishing.
The aesthetic level of carbon fiber is good since colors and texture can be customized. The
structure of carbon fiber enables the building of a light frame which is a desirable feature for any
mountain bicycle (Aguilar, 2019). During the operation cycle, carbon fiber is durable, and it can
retain and release shock due to terrain irregularities. Little energy is used for the propulsion of
the bike through the steep gradient of the terrain due to the overall weight of the bicycle (Tsai,
2018).
Thermoplastics
This is a group of polymers which can be reheated and reshaped into different forms.
Thermoplastics have an excellent product finish saving cost for possible secondary production
processes .thermoplastics have low ability to absorb shock (Peres, Pires, & Oréfice, 2016). The
polymers have low elastic modulus hence low strength (Callister, 2007). Thermoplastics are
affected by high temperatures therefore not desirable to be used in high heat generating areas in
the bicycle.
II. Gear set
Transmission of power in a bicycle is done through a game of gears system. The gear
materials should be having a low coefficient of friction, be self-lubricating, have sufficient