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Effect Of Laser Power On Temperature Evolution, Brazing Phases And Mechanical Properties Of Cu/cu Brazed Joint / Yus Erny Amirah Mohd Yusof

By:

Yus Erny Amirah Mohd Yusof [author.]

Material type: Text

text
text

Media type:

unmediated
computer

Carrier type:

volume
computer disc

ISBN:

THE0009672 (Local)

Subject(s):

Dissertation note: Thesis (Master of Science) -- Universiti Malaysia Pahang – 2023 Abstract: Brazing technique via heat source has been employed in joining the pure copper. Brazing parameters and laser power are crucial factors in determining the joint quality during indirect laser brazing. This research investigated the effects of laser power on brazing temperature, temperature evolution, brazing phases, the strength of the joints, filler spreadability and surface fracture on copper alloys. The brazing process was carried out in a vacuum chamber with a constant vacuum pressure of 400 Pa over 66 seconds for each sample to ensure that the filler metals were melted completely. Cu-78.3Ni-9.9Sn-4.0P-7.9 (MBF2002) was used as a filler metal to braze the Cu/ Cu joints. When the laser power varied from 30 W to 50 W, the brazing temperature increased gradually, hence creating a temperature profile where the brazing phases were identified. With increasing the laser power, the tensile shear strength of the joint also increased. The maximum value of shear strength (159.27 MPa) was obtained at 50 W of laser power compared with another laser power. The shear strength increased by 34.02%. The fracture surfaces were examined under an optical microscope and 3D measuring laser microscope to observe the filler spreadability and surface roughness. It showed that the roughness increases as the laser power increases. The fracture surface occurred at the filler metal and characterized by brittle fracture. In addition, the EDX was carried out for the 50 W laser power sample to identify the microstructure and phase composition of joint interfacial. The microstructure consisted of Cu (Sn- rich) and a Cu-Ni-P phase formed at the brazed joint. Based on the results, the actual process that occurs behind the laser brazing are known through the brazing phases involved.

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Holdings ( 2 )
Title notes ( 4 )

Holdings
Item type	Current library	Call number	Copy number	Status	Date due	Barcode
Restricted Collection	UMPLIB PEKAN	FTKMA .Y87 2023 r Thesis (Browse shelf(Opens below))	1	Not for loan		T000002416
Restricted Collection	UMPLIB PEKAN	CD13373 (Browse shelf(Opens below))	1	Not for loan		T000002417

Faculty of Mechanical and Automotive Engineering Technology

Thesis (Master of Science) -- Universiti Malaysia Pahang – 2023

Includes bibliographical references

Brazing technique via heat source has been employed in joining the pure copper. Brazing parameters and laser power are crucial factors in determining the joint quality during indirect laser brazing. This research investigated the effects of laser power on brazing temperature, temperature evolution, brazing phases, the strength of the joints, filler spreadability and surface fracture on copper alloys. The brazing process was carried out in a vacuum chamber with a constant vacuum pressure of 400 Pa over 66 seconds for each sample to ensure that the filler metals were melted completely. Cu-78.3Ni-9.9Sn-4.0P-7.9 (MBF2002) was used as a filler metal to braze the Cu/ Cu joints. When the laser power varied from 30 W to 50 W, the brazing temperature increased gradually, hence creating a temperature profile where the brazing phases were identified. With increasing the laser power, the tensile shear strength of the joint also increased. The maximum value of shear strength (159.27 MPa) was obtained at 50 W of laser power compared with another laser power. The shear strength increased by 34.02%. The fracture surfaces were examined under an optical microscope and 3D measuring laser microscope to observe the filler spreadability and surface roughness. It showed that the roughness increases as the laser power increases. The fracture surface occurred at the filler metal and characterized by brittle fracture. In addition, the EDX was carried out for the 50 W laser power sample to identify the microstructure and phase composition of joint interfacial. The microstructure consisted of Cu (Sn- rich) and a Cu-Ni-P phase formed at the brazed joint. Based on the results, the actual process that occurs behind the laser brazing are known through the brazing phases involved.