Mechanical Engineering Report on Alloy Applications and Properties

This report delves into the applications and properties of various alloys commonly used in mechanical engineering. It begins with an introduction to corrosion, wear, and fatigue, highlighting the importance of surface treatments like laser cladding. The report then explores the principles and techniques of laser cladding, including the impact of dilution and microstructure on coating properties. Detailed information on cobalt-based alloys (including Stellite alloys and Tribaloy), nickel-based alloys (Inconel and Hastelloy), iron-based alloys, and aluminum-based alloys is provided, including their compositions, applications, and typical properties. A case study on laser cladding of a cobalt alloy is included, covering the experimental setup, results, and discussion of the process. The report concludes with a summary of the findings and a list of references. This assignment is an excellent resource for understanding the selection and application of alloys in mechanical engineering.

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Contents
Introduction and Synopsis...........................................................................................................................4
Principles and techniques............................................................................................................................4
Cobalt-based alloys..................................................................................................................................6
Applications and properties.................................................................................................................6
Nickel-Based alloys..................................................................................................................................9
Applications and properties.................................................................................................................9
Iron based Alloys...................................................................................................................................11
Applications and typical properties...................................................................................................11
Aluminum-based alloys.........................................................................................................................16
Application.........................................................................................................................................16
Case Study.................................................................................................................................................17
LASER CLADDING OF COBALT ALLOY.....................................................................................................17
Abstract.............................................................................................................................................17
Introduction.......................................................................................................................................17
Experimental.....................................................................................................................................19
Results and Discussion.......................................................................................................................22
Summary and Conclusion..................................................................................................................32
REFERENCES..........................................................................................................................................35

Introduction and Synopsis
Corrosion, wear and fatigue are the three primary processes that are known to be responsible for
limiting the productive life of any product of engineering. Their combined efforts and impacts
strongly affect the economy of most of the countries. This is because they cause repair, material
replacements, maintenance among others that attract various charges. Moreover, control of wear
and reduction of corrosion is important to increase the lifetime of the biosystems and machinery
in order to make these products of engineering more efficient (Chen and de Aldana 2014). Such

activities also lead to the conservation of resources of materials, improvement of safety and
saving of energy. For these reasons, the processes of lowering derivative phenomena have been
under development.
Laser cladding refers to upcoming technology in the field of engineering that deals with the
surface treatments. The versatility, high energy density and selectivity property of the laser beam
normally allow for the production of a high-quality coating of metallic type through fusion
bonding to the substrate. This is also characterized by low dilution. Rapid prototyping and
component repairing apply the specific characteristics of this technology. The quality of the laser
and the properties are directly influenced by the choice of the material, cladding equipment,
parameters of the process and finally the duration of the exposure. The quality is also sensitive to
the complexities that occur during the processes.
Principles and techniques
The model definitions that can be used in the description of the entire exercise to predict the
properties of coatings, therefore, become very fundamental. Some of the materials that are used
in the laser cladding include alloys of various substances. Also, process of dilution negatively
affects the warm oxidation conduct of the amalgam. The oxidation rate increments on expanding
dilution and disastrous oxidation have been seen in the most exceedingly terrible preparing
conditions, for example, elevated cladding and high temperature. Indeed, even with restricted
dilution at interfaces, the relative diminishing in the oxidation rate between the first as well as
the second stage essentially indicates the reduction of the oxidation conduct amid test samples.
An unmistakable relationship amongst microhardness and process of dilution is uncovered
likewise in the cladds created with the NiBSi combination. Once more, this conduct is brought
about by the microstructure of the composite. On expanding weakened interface, microstructure

advances in two distinctive ways. The microstructure turns out to be increasingly dendritic since
iron dilution changes the compound creation of the NiBSi amalgam. This is relied upon to move
a long way from eutectic focuses along these lines thereby promoting proeutectic fusion.
In addition, with the expansion in weakening process, eutectic morphology advances towards
the development of the γ-nickel-boride eutectic and a silicon-rich component to the detriment of
the nickel-boride and nickel-silicide eutectic, which will, in general, vanish for the case of this
alloy. At the point when an alloy of iron has utilized a role as a substrate, the NiBSi combination
demonstrates the equivalent microstructural change; in the expansion, on expanding weakening
interfaces and the effectiveness of the graphite layer is confirmed. The morphology of this
graphite appears to change from spheroidal to vermicular and then falls on a ratio of G/R, for
example on expanding weakening zones (Qiu and Liu 2013). In the coatings created with a
blend of either Stellite12 or Stellite 21 powder or tungsten carbides, carbides disintegration
happens amid laser cladding and affects the last properties of the coatings used. Disintegration is
to a great extent affected by the preparing conditions during the examination. Disintegration gets
higher with the expansion in the laser control and when the substrate is preheated, fundamentally
in view of the increment in temperature of the liquefy pool which improves disintegration
marvels. Synthetic structure of the Stellite base powder additionally impacts disintegration: a
lower substance of tungsten and carbon supports the disintegration of the tungsten carbides.
In the network where no tungsten and 0.25% of carbon are available, carbides disintegration
prompts an increment in the microhardness, which beats the reduction in the content, along these
lines prompting an increment in the hardness of the coating itself. On the inverse, framework
microhardness of the stellite rich in tungsten and carbon does not get any benefit by carbides

disintegration: as an outcome, the hardness of the coating somewhat diminishes because of the
reduction of the content (Zhou et al 2016).
Cobalt-based alloys
Alloy 1
Type of powder
Alloy 1.
Composition in Nominal class.
W 12.0, Cr 31.0, Si 1.0, C 2.5 and Cobalt.
FST p/n: M-489.93 M-489.95.
The range of size:-125+45μ -150+45μ.
Applications and properties.
 These are cobalt alloys that are made from the composition of a chemical similar to
stellite
 It is considered to be the hardest of the known standard alloys from cobalt.
 It can keep its hardness up to a standard of 725 degrees.
 It is more sensitive to crack than other cobalt alloys.
 It has a high content of carbide in the matrix of cobalt. This leads to excellent resistance
to abrasion and erosion of solid particles.
Type of Powder
Alloy 6.

Composition In Nominal class
W 5.0 ,Cr 28.0, Si 1.0, C 1.0 and Co.
FST p/: M-489.93 M-489.95.
The range of Size: -125+45μ -150+45μ.
Applications and properties
 It is the most commonly used alloy that provides excellent resistance to various forms of
mechanical and chemical degradation over a big range of temperatures.
 It has perfect resistance to cavitation and impact.
 It is capable of keeping hardness up to 500 degrees.
Alloy 12
Type of powder Alloy 12
Composition In Nominal: 8.5,Cr 30.0, Si 1.5 ,C 1.5 and Co.
FST p/n: M-481.93 M-481.95.
Range size: -125+45μ -150+45μ.
Applications
 This is a cobalt-based alloy that has a similar chemical composition as stellite 12.
 It has better resistance to erosion and corrosion than alloy 6.
 It has better resistance to thermal shocks and impacts.
Powder type :T-400

Composition in Nominal class: Mo 28.0, Cr 8. 5,Si 2.5 and Co.
FST p/n: M-494.93 M-494.95.
Range size: -125+45μ -150+45μ.
Applications
 This is an alloy with a similar chemical composition as Tribaloy T-400.
 It has high resistance to corrosion.
 It has high resistance to oxidation at higher temperatures.
 It has high resistance to galling with other metals as well as wear.
Powder type: T-800
Composition in Nominal class: Mo 28.0 ;Cr 17.0; Si 3.0 and Co.
FST p/n: M-499.93 M-499.95.
Range Size: -125+45μ -150+45μ.
Applications
 This is an alloy of cobalt whose chemical compositions the same as that of Tribaloy T-
800.
 It has high resistance to corrosion.
 It has high resistance to the effects of the oxidation at relatively elevated temperatures.
 It has high resistance to galling and war effects. This translates to hot hardness properties
Nickel-Based alloys
Powder type: Alloy 625.

Composition by Nominal class: Cr 21.5 ,Mo 9.0 Nb 3.5 ,Fe<1.5, and Ni.
FST p/n: M-341.93 M-341.95.
Range size: -125+45μ -150+45μ.
Applications and properties
 These are Nickel based alloys that have a similar chemical composition as Inconel 625.
 It has excellent resistance to corrosion this suitable for wide range of use in
environmental work.
 High resistance to corrosion of stress that causes cracks.
 The resistance of alloy to temperatures of oxidation.
 They are normally used in in the repair of other nickel-based unalloyed and alloy that are
underlying the internal streets.
Type of Powder: Alloy C-276.
Composition by Nominal class: Cr 16.0; Mo 15.5; W 4.0; Fe 3.0 and Ni
. FST p/n: M-341.93 M-341.95.
Range Size: -125+45μ -150+45μ.
Applications and properties.
 This is basically an alloy of Nickel that is having properties the same as that e of
Hastelloy C276.
 It has perfect resistance to corrosion in mineral acids that are hot and contaminated.
 It has high resistance to strong oxidizers and chlorine gases that may be wet.
 It is also resistant to cracking and corrosion of crevice.

Type of Powder: NiCrSiB 40HRC.
Composition by Nominal class.: Cr 10.0; Fe 2.5 ;Si 3.1 ;B 2.1 ;C 0.4 and Ni.
FST p/n: M.772.93 M-772.95.
Range Size: -125+45μ -150+45μ.
Applications and properties
 NiCrBSi alloys have good resistance to wear and corrosion.
 They are normally used in cases where higher machinability is required.
 The range of hardness is actually 40 HRC which is normally considered sufficient.
Type of Powder: NiCrSiB 50HRC.
Composition by Nominal.:Cr 12.5; Fe 3.8 ;Si 3.7 ;B 2.2 ;C 0.55 and Ni
FST p/n:M-776.93 M-776.95.
Range size: -125+45μ -150+45μ.
Applications and properties
 It has perfect resistance to wear corrosion. The resistance to abrasion can be reduced by
the use of Tungsten Carbide.
Powder Type: NiCrSiBCuMo.
Composition by Nominal categories: Cr 16.5; Fe 3.0 ;Si 4.5 ;B 3.8 ;C 0.55; Cu 2.1 ;Mo 5.0 and
Ni.

FST p/n: M-777.93 M-777.75.
Range Size: -125+45μ -150+45μ.
Applications and properties
 The alloys of NiCrBSi are normally obtained through the addition of Cu and Mo.
 It has a perfect corrosion resistance in the solution of alkaline and acidic.
 They have perfect resistance to such media as compared to CU and Mo alone.
Iron based Alloys
Type of powder:316L
Nominal Composition’s 17.0 ;Ni 12.0; Mo 2.5 ;Si<0.75;C<0.03 and Fe.
FST p/n:M-684.93 M-684.95.
The range of size: -125+45μ -150+45μ.
Applications and typical properties.
 It is resistant to corrosion up to a temperature of 400 degrees Celsius.
 It allows for easy machining and possible mirror finishing.
Powder Type: 431.
Nominal Composition
FST p/n :M-687.93 M-687.95.
The range of size -125+45μ -150+45μ.
Applications and typical properties

 This is commonly referred to as Martensitic steel of nickel chromium.
 It has better resistance than steel 410 or steel 403 which offers good resistance to
corrosion (Qiu and Liu 2013).
 It has perfect wear resistant.
Additives of Manufacturing Powders
Type of Powder: Fe-Based | 20HRC (316L).
Composition in terms of Nominal: Cr 17.0; Mo 2.0; Ni 12.0; Mn 2.0; Si 0.75 and Fe.
FST p/n: AM-613.33
Size of range: -53+20μ.
Applications and properties
UNS S31603 DIN 1.4404
Physical properties
 Its average density: 8.0 when powder form.
 The Melting point (°C): 1370 – 1400
 It has a thermal conductivity of 16.2 W/mK
 The thermal Coefficient of Expansion (°Cx10-6): 15.9.
Features/Description
 This particular material has excellent corrosion and mechanical resistance properties
 Its hardness value is high