1. Final report of internship
Material testing and NDT center, AMF, PAC Kamra
Submitted by: Ayesha Butt
Registration number: 2011-NUST-SCME-BE-Mtl-98
Internship duration: 14-7-2014 to 25-7-2014
Submitted to: Sir Khurram Rehman

2. Introduction:
My stay at PAC was from 14-7-2014 to 25-7-2014. During this stay I have visited heat treatment
shop, surface treatment shop, NDT department, sub assembly, final assembly and FTS.
Heat treatment shop:
To check the process qualification (PQ) of a system two types of tests are performed:
1. TUS(temperature uniformity test)
This test is performed to check the temperature variation across a system. This test is
carried out after every 6 months.
2. SAT(system accuracy test)
This test is carried out to check the variation between calibrated temperature and a
tester thermocouple. This test is carried out at the end of every month.
Based on these two tests furnaces are divided into different classes. Some of them are:
Class I temperature variation of ±3oC
Class II temperature variation of ±5oC
Class III temperature variation of ±10oC
Non-Ferrous Alloys are heat treated in two types of furnaces:
 Box type furnace
 Pit/well type furnace
Maximum temperature reached by these furnaces is 650oC.
Solution heat treatment of non-ferrous alloys is also done here in Nitrate bath which comprises
of 50% KNO3 and 50%NaNO3.
Ferrous Alloys are heat treated in vacuum furnace. They are of two types:
 Horizontal vacuum furnace
 Vertical vacuum furnace
Specifications of vertical vacuum furnace are:
Maximum temperature = 1320oC
Maximum operating temperature = 1200oC

3. After heat treatment of samples, hardness is checked by using Rockwell, Brinell or Vicker
hardness testing machines.
Surface treatment shop:
The main purpose of surface treatment shop is decoration and protection from corrosion.
Three types of surface treatment are done here:
 Chemical milling
 SAA( sulphuric acid anodizing)
 CAA (chromic acid anodizing)
Different containers are placed here to perform different types of functions. For example
emulsion cleaning chamber for degreasing the part, cold and hot water chamber for cleaning of
parts, chemical milling chamber, and chambers to perform SAA and CAA.
PQ of SAA and CAA is done by following tests:
i. Salt spray
ii. Coating weight
iii. Moist adhesion notch
iv. Impact test
PQ of chemical milling is done by following tests:
i. Surface roughness
ii. Line error deviation
iii. Surface defect
iv. IGC( intergranular corrosion)
NDT (non-destructive testing)
1. X-Ray or Radiographic testing:
In this technique hidden cracks are inspected.
 Industrial X-Ray flaw detector:
In this machine very high energy beam of X-Rays is focused on any material type
to inspect casting and welded parts.

4.  Panaramy X-ray machine
In this machine tungsten source is used. Rays are ejected at 360o angle which
gives circumferential shots.
X-Ray is developed in dark room and is illuminated by specially designed illuminator to
study the image in which cracks appear as lines and pores appear as dots.
2. MPI( magnetic particle inspection)
It is used for ferrous materials only to study surface and sub-surface cracks. The material
is sprayed by magnetic ink. The cracks appear as black lines. Material is demagnetized
after the test is performed.
Following are used for MPI:
 Magnetic powder flaw detector
 Yoke magnetization
3. Eddy current flaw detector:
It is used to detect skin or surface cracks. It has probes to scan electrically conductive
materials. For scanning best contact of probe and surface is necessary. There are three
types of probes:
 Surface probe for flat surfaces
 Encircling probe for rods or pipes
 Inner surface probe for inner surface of rods and pipes
Spectrometry:
There are two types of spectrometric analysis:
 Qualitative analysis for detection of elements
 Quantitative analysis for measuring the composition
1. Spectroscope:
It is used for qualitative analysis. Spark is produced when specimen is placed near
electrode which gives different wavelength for every element which falls in visible
region. For Al alloy Fe electrode is used and for Fe alloys Cu electrode is used. For soft
alloys maximum time for spark is 20-120 seconds.
2. Direct reading spectrum:
It is used for quantitative analysis.it works in UV and visible range.it shows composition
in percentage.in this machine 52 detectors are used which can identify 32 elements at a
time.

5. 3. Carbon-sulphur analyzer:
It is more precise than direct reading spectrum and it works in IR range. It gives
measurements in ppm or ppt. it works on the principle of gravimetric analysis.
4. Atom absorption:
It is also used for quantitative analysis. It works in UV and visible range.liquid sample is
used and it gives readings in ppm or ppt.
5. ICP(inductively coupled plasma) :
It also measures quantitatively. Liquid sample is used and it measures in ppm and ppt.
organic samples can also be detected along with inorganic samples.
Physical lab:
1. Impact test:
This test is used to check toughness of a material. There are two types of specimens:
 Charpy (horizontal sample)
 Izod (vertical sample)
2. Wire winding test:
It uses wire of any size. This test is performed to check cladding of wire.
3. Tensile testing:
Longitudinal stress is applied to check tension in a material. Small amount of stress is
applied to check tension in non-metallic materials like rubber and greater amount of
stress is applied on metallic materials.
4. High performance fatigue test:
It is used to check fatigue life and endurance limit. Specifications of the machine are:
Maximum static load = ±100kN
Maximum dynamic load = 50kN
Frequency range = 80-250Hz
5. Pressure test:
It is a compression test in which bearings are checked.

6. 6. High temperature creep duration test:
In this test constant load is applied at higher temperature. This is used to check
hydrogen embrittleness. Time required to perform this test is 200 hours.
7. Hardness test:
Hardness test is performed to check the resistance of a material against a force. Three
types of hardness machines are used:
 Rockwell
 Brinell
 Vicker
Metallurgical lab:
In this lab, Sample is first mounted then grinded and polished. It is then viewed in microscope
to study cracks at micro level, IGC, eutectic failure and HTO surface.
POL (paint oil lubricant):
Different types of tests are performed to check contamination and viscosity of oils and
lubricants.
 Particle counter
 Distillation
 Drop point
 Grease penetration test
 Cu strip corrosion test
Sub-Assembly, final assembly and FTS:
Fuselage, wings, vertical and horizontal tail are build rivets and nuts and bolts. Materials used
are 2024 and 7075. Then different tests are performed in final assembly for example continuity
and power check flight control test, installation of engine, quality inspection and seat
installation.
Planes are finally checked for air worthiness in FTS.