Inspection Project Report Final.docx

INSPECTION AND TESTING OF MATERIALS LAB Project report Submitted By: Group: B-II Samra Fatima (160301019) Osama Saleem (160301020) Zeeshan (160301021) Zain Hanif (160301023) Zaryab Asghar (160301022)

Submitted to: Engr. Faisal Mustafa

Date: 07/01/2018

Table of Contents 1.

ABSTRACT .................................................................................................................... 2

2.

OBJECTIVES ................................................................................................................. 2

3.

INTRODUCTION .......................................................................................................... 3 a.

Vickers hardness test ............................................................................................... 3

b.

Compression test...................................................................................................... 3

c.

Charpy impact test ................................................................................................... 5

4.

APPARATUS ................................................................................................................. 5

5.

SAMPLE PREPARATIONS .......................................................................................... 6 i.

Vickers hardness test: .............................................................................................. 6

ii.

Compression test...................................................................................................... 6

iii.

Charpy impact test ................................................................................................... 6

6.

PROCEDURES............................................................................................................... 6 a.

Vickers hardness test ............................................................................................... 6

b.

Compression testing ................................................................................................ 7

c.

Charpy Impact test ................................................................................................... 8

7.

RESULTS, DISCUSSIONS & COMPARISONS .......................................................... 9 i.

Vickers hardness test ............................................................................................... 9

ii.

Compression test: .................................................................................................... 9

Sample: .................................................................................................................................. 9 Readings:.............................................................................................................................. 10 The value of compressive strength we obtained was 184 N/mm2 and according to ′MATWEB® Material Property Data’ the compressive strength of brass lies between 82.7 - 260 MPa. ................................................................................................................... 10 Precautions: .......................................................................................................................... 10 iii.

Charpy impact test: ................................................................................................ 11

Precautions: .......................................................................................................................... 11 Sources of errors: ................................................................................................................. 11 8.

CONCLUSIONS........................................................................................................... 11

PARTICIPATION TABLE ..................................................................................................... 12 9.

REFERENCES ............................................................................................................. 13

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1. ABSTRACT In this project report we have determined the material of an eight inch circular rod by doing different types of destructive and non-destructive testing. Three tests were being performed as per ASTM standard specimens. The tests were Vickers hardness test to determine hardness of that material, Charpy impact test to calculate impact energy and Compression test to determine the compressive strength. After these test, all the values were compared to the standards and the material identified that was cartridge brass.

2. OBJECTIVES Three of the main objectives include;    

To perform Vickers hardness test. To perform Charpy impact test. To perform Compression test. To compare all the values obtained from the tests to the properties of other materials and find which type of material is used in these experiments.

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3. INTRODUCTION Hardness of a material is an important factor by which the applications of the material are determined. We are performing this experiment to determine the hardness of Brass sample using Vickers Hardness Test. In this experiment we will determine the hardness of Brass Sample at different points through Vickers hardness testing machine by indentation and finding the average between the diagonals of the indentation to find the VPN (Vickers Pyramid Number) The compressive test is opposite in nature to the tensile test. In this testing, a circular rod according to E-8 ASTM standards specimen is subjected to control compression until some buckling is observed, where as in Charpy impact test we take a rectangular specimen according to ASTM standards to determine impact energy of that specimen.

We are performing destructive testing techniques to determine the specimen iiiiii-

Vickers hardness test Compression test Charpy Impact test

a. Vickers hardness test In the Vickers hardness test, an optical method, the size of indentation (the diagonals) left by the indenter is measured. It involves a diamond indenter in the form of a square-based pyramid with an apex angle of 136˚. The indenter is being pressed under load for 10 to 15 seconds into the surface of the specimen under test. The result is a square-shape indentation. After the load and indenter are removed the diagonals of the indentation d are measured. The larger the indent left by the indenter at a defined test force in the surface of a work piece (specimen), the softer the tested material. Figure 1Schematics of Vickers Hardness test

b. Compression test The most commonly used testing machine is known as Ultimate Testing Machine. This type of machine has two crossheads; one is adjusted for the length of the specimen and the other is driven to apply tension to the test specimen .There are four main parameters: force capacity, speed, precision and accuracy. Force capacity refers to the fact that the machine must be able to generate enough force to fracture the specimen. The machine must be able to apply the force quickly or slowly enough to properly mimic the actual application. Finally, the machine must be able to accurately and precisely measure the gauge length and forces applied.

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Alignment of the test specimen in the testing machine is critical, because if the specimen is misaligned, either at an angle or offset to one side, the machine will exert a bending force on the specimen. If the initial portion of the stress–strain curve is curved and not linear, it indicates the specimen is misaligned in the testing machine. The strain measurements are most commonly measured with an extensometer, but strain gauges are also frequently used on small test specimen. Newer test machines have digital time, force, and elongation measurement systems consisting of electronic sensors connected to a data collection device (often a computer) and software to manipulate and output the data.

Figure 2: Universal testing machine

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c. Charpy impact test The standard test for measuring impact energy is the Charpy test. This gives an indication of the characteristics of the material during fracture. An arm is swung down in a pendulum motion to impact with the test material. The energy required to fracture the sample is recorded. The Charpy impact specimens are produced as a bar containing a notch. The swinging arm of the impact tester provides the impact. The sample will fracture along the plane indicated by the red line below. The arm continues through after impacting and the height it swings to is a direct indication of the amount of energy absorbed during fracture.

Figure 3schematics of Charpy impact test

4. APPARATUS       

Vickers hardness tester Universal testing machine Meta cut Lathe machine Milling machine Impact testing machine Vernier caliper

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5. SAMPLE PREPARATIONS For the preparation of sample according to ASTM standards we had an 8 inch rod shaped

i.

Vickers hardness test:

ASTM Standard: E92 – 17 (flatness and smoothness of the surface of specimen are the basic requirements)     

ii.

Firstly we cut the sample of length mm After we did facing with lathe machine to get finish surface With the help of grinder surface get more smoother Finally has been prepared according to standards For another complementary test we also made a cylindrical sample

Compression test

ASTM Standard: ASTM E9 – 09 (Diameter = 13mm, length = 38mm)   

iii.

We cut the rod of 3.8mm according to ASTM standard of compression test specimen with hacksaw We did facing for an even surface Sample prepared as per standards.

Charpy impact test

ASTM Standard: ASTM E23-18 (10-10-55 mm ‘Length- Thickness-Width’, 2mm V-Notch)   

 

Firstly cut the sample 60mm with the help of hacksaw. With the help of lathe machine facing was done and the sample reduced to 55mm. To prepare the sample according standards, we used milling machine to convert 16mm diameter of rod to flatten 10-10mm (thickness-widtht) from each side. Triangular file were used to get V-notch of 2mm at the center of sample. Standard ASTM sample were finally obtained.

Figure 4: Standard ASTM E23-18 sample

6. PROCEDURES a. Vickers hardness test 

Place the specimen on the anvil under the indenter, the anvil can be disk like for flat surface sample or V-shaped for cylindrical samples

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   

     

Make sure the surface of the specimen is parallel to the surface of the anvil Use Hand wheel to move the elevating screw and bring the specimen close enough that the crystal grains are visible in the microscope Place the indenter on position and select the load (kgf) Start the Machine, set the dwell time, and Press the start button on the machine to start. The Machine will apply the load wait for a period of time set as dwell time than the machine will remove the load Calculate the diagonal’s using the microscope Repeat this process to get three indents on the specimen by moving the specimen on the anvil Observe and record the average diameter of indentation through a scope Repeat all the steps for other specimens if any Press the off button on the Machine Follow all the precautions of the Experiment and the safety measure required for this experiment

b. Compression testing 

The original dimensions of the specimen like original dia., gauge length etc. is to be measured



Turn on the machine. Place the brass specimen in the center of loading area



Lower the piston against the top of brass specimen by pushing the lever. Don’t apply load just now. Just place the piston on top of specimen so that it’s touching that



Now the piston is on top of specimen. It is the time to apply load. Pull the lever into holding position. Start the compression test by pressing the zero button on the display board



By turning pressure increasing valve counter-clockwise, adjust the pressure on piston so that it matches brass compression strength value. Apply the load gradually without shock



Observe the brass specimen. When it begins to break or buckling stop applying load



Record the ultimate load on paper displaying on machine’s display screen



Match your record once again with the result on display screen. The result should still be on display screen. And then turn off the machine



The result we got from testing machine is the ultimate load to bend the brass specimen. The load unit is generally in lb. We have to convert it in newton (N). Our purpose is, to know the brass compressive strength

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c. Charpy Impact test 

Choose the appropriate hammer and place it on the Starting Position



Check the zero calibration of the impact tester to check the energy absorbed by air resistance. The energy absorbed is zero error which is subtracted from all results Take the standard specimen (ASTM E23-18) for Charpy



   

Impact test and place it on the Anvil while keeping the notch opposite and in line with point of impact Move the needle to the maximum (in this case i.e. 150 J) Clear the surrounding Space to avoid injury and Start the machine by using the controller and press impact After the hammer arrives at its starting position again, stop the machine and place it on rest position Note the reading on the scale respective of the hammer used

Figure 5: Clamped sample

(i.e. smaller scale)

Figure 6: After the test

Note: Test was performed at room temperature.

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7. RESULTS, DISCUSSIONS & COMPARISONS i.

Vickers hardness test VPN

No.

Specimen

Surface being Tested

Average Diagonal (kgf/mm2)

Brass (cylinder) CURVED SURFACE

1

0.52+0.552 2

= 0.536

73.9

0.482+0.52 2

= 0.501 69.6

0.49+0.541 2

Brass (sample size)

2

FLAT SURFACE

= 0.516

0.435+0.504

99.4

= 0.432

2

0.504+0.436

84.0

= 0.470

2

0.494+0.52 2

64.5

= 0.507

72.1

The above table shows the VPN numbers of the brass samples obtained by performing the test three times each. The variation in hardness is due to the alloy nature of the samples these values indicate the change in hardness value due to the load applied in different direction and points/spots. The average VPN is taken as hardness of the sample for application which is 85.1 kgf/𝑚𝑚2 and it close to standard VPN of brass (i.e. 91 HV). A little variation is due to the performance of experiment or may be the sample was not flat enough.

ii.

Compression test:

Sample: Shape = Cylinder Specimen material = Brass Ultimate force = 31.48KN

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Strain rate = 2mm/min Readings: Gauge length = 3.8mm Diameter = 13mm Area = 132.74mm2

Compressive strength = 24.5kN / 132.74 mm2 = 184.58 N/mm2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Figure 7: Stress-Strain curve for compression test of brass

The value of compressive strength we obtained was 184 N/ mm2 and according to ′MATWEB ® Material Property Data’ the compressive strength of brass lies between 82.7 260 MPa. Precautions: (a) The specimen must be kept at the center of cross-head so that a uniform compressive loading can be assured on the specimen. (b) The loading is to be increased gradually. (c) The size of the specimen is to be measured accurately.

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iii.

Charpy impact test:

Temperature= 16 ᵒC Energy loss due to air resistance = 0J Sample length = 55mm Sample height = 10mm Sample width = 10mm Energy absorbed after impact test (our sample) = 8.2J The energy absorbed in the sample after impact test were 8.2J which is not comparable to standard brass impact energy that is 11.1J this is due to the span length of the charpy test machine was not as per standard and we were unable to fix that because of the L-key wasn’t available at that time. May be sample was not prepared according to the exact standards (i.e. if notch is deeper than 2mm the energy absorb will be less) or may be some of the material’s fault. However it was closer to value of brass specimen.

Precautions:    

The destructive testing is performed, while performing experiment one should wear protective glasses. Keep the distance about 3 feet at least from testing machine. Hammer should be attached perfectly, accident may happen. Safety precautions should be taken to protect personnel from the swinging pendulum, flying broken specimens, and hazards associated with specimen warming and cooling media.

Sources of errors:   

Span length may vary from standardizations i.e. 45mm While testing air resistance or impact strength energy one may get negative energy value. Hammer may not be in the line of notch.

8. CONCLUSIONS Compression test is the fundamental test which is done to determine the material compressive strength under a load. The maximum stress a material can sustain under a load is determined. Compression testing is often done to fracture point or up to buckling of a material.in this experiment, we used Brass cylindrical rod then we apply load on the sample by moving the crossheads together. During the test, the sample is compressed and deformed and when

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buckling happens, we unload the specimen and with the help of stress-strain curve we can determine the compressive strength of the sample. On performing the successful compression test on the sample, we concluded that the Brass has more compressive strength then Aluminum and has less compressive strength as compared to Mild steel. Hardness testing plays a vital role in materials testing, quality control, and acceptance of components. The data is needed in order to verify the heat treatment, structural integrity, and quality of components that will help determine if a material has the properties essential for its proposed use. Establishing a correlation between the desired material property and the hardness result allows this, thus making hardness tests extremely useful in R&D and industrial applications and also in assuring that the materials utilized in the things used every day contribute to a well-engineered, safe and efficient world Charpy impact test helped us to determine the energy (impact) absorbed by the specimen which helped us in the determination of the metal. The ductile-brittle transition temperature (DBTT) may be derived from the temperature where the energy needed to fracture the material drastically changes. However, in practice there is no sharp transition and it is difficult to obtain a precise transition temperature (it is really a transition region) From these three tests, the values we achieved were closer to brass but the key thing was to check what type of brass that was? Color observation totally rejected the white brass because of its color. The values we got were closer to the values of cartridge brass. It contains 70 percent copper and 30 percent zinc and also alpha-brasses also contains morae than 35 percent zinc and more than 65 percent copper, so our specimen was cartridge brass which is present in the types of alpha-brasses.

PARTICIPATION TABLE

Samra Fatima

Osama Saleem

Zeeshan

Zain Hanif

Zaryab Asghar

Charpy,Compression

Charpy

Compression

Hardness

Meta Cut

Name of Tasks Standards Sample Preparation Vickers Compression Charpy Documentation Comparison Compilation & Formation

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9. REFERENCES 

Overview of materials for Brass. (2015). 𝑀𝐴𝑇𝑊𝐸𝐵 ® Material Property Data. Retrieved from http://www.matweb.com/search/DataSheet.aspx?MatGUID=d3bd4617903543ada92f4c101 c2a20e5



Learn About the Different Brass Types .(2016). The balance commodities. Retrieved from https://www.thebalance.com/brass-types-3959219



High Strength Yellow Brass. (2013). Azo Materials. Retrieved from https://www.azom.com/article.aspx?ArticleID=6479



ASTM INERNATIONAL Helping our world work better. Retrieved from https://www.astm.org/ ( for ASTM Standards Approval)



ASTM E9 Compression Testing of Metallic Materials at Room Temperature. (2012). Test Resources. Retrieved from https://www.testresources.net/applications/standards/astm/astm-e9-compression-testingof-metallic-materials-at-room-temperature/



Mr. Sahadev Shivaji Sutar. (2016). Analysis of Ductile-to-Brittle Transition Temperature of Mild Steel . Department of Mechanical Engineering, Solapur University. Retrieved from http://oaji.net/articles/2014/1511-1419830589.pdf



Cantrell. A. (2016). Hardness of Brass. University of Washington. Retrieved from http://www.materialseducation.org/educators/matedu_modules/docs/Hardness_of_Brass_ Slides.pdf



Nikita Khlystov. (2013). Uniaxial Tension and Compression Testing of Materials. Retrieved from http://web.mit.edu/dlizardo/www/UniaxialTestingLabReportV6.pdf



Olemule T. Owens (2010). Mechanics of Material Laboratory. Retrieved from https://www.pdfcoke.com/doc/42833168/Compression-Lab-Report



EA Nyberg, VV Joshi (2012). Summary of Compression Testing. Retrieved from https://www.pnnl.gov/main/publications/external/technical_reports/PNNL-21932.pdf



Digital Vernier Caliper Inch Metric Conversion. (2017). Conversion-StainlessElectronic-Measuring. Retrieved from https://www.amazon.co.uk/ConversionStainless-Electronic-Measuring-OKPOW/dp/B071CNY44N



The Universal Testing Machine ready for a tensile test (2016). Researchgate. Retrieved from https://www.researchgate.net/figure/The-Universal-TestingMachine-ready-for-a-tensile-test_fig24_306017907

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

History Studies International Journal of History. (2015). bibme. Retrieved from https://www.twi-global.com/technical-knowledge/faqs/faq-what-is-charpytestinghttps://www.mercerindustries.com/mercer_product/saw-files/

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