Volume 10, Issue 4 (12-2020)                   ASE 2020, 10(4): 3381-3393 | Back to browse issues page

‎ 10.22068/ase.2020.521

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Effect of NOCOLOK® Flux Dry-off Temperature on Mechanical Properties of Brazed Joint of Automotive Aluminum-Based Heat Exchangers
Seyyed Ali Akbar Hashemi Milani , Reza Tavangar , Maziyar Azadbeh , Ibrahim Kahinpoor , Hossein Sadeghi-Nasab
sahand university of technology
Abstract:   (7219 Views)
Drying temperature of the flux at normal atmosphere has a crucial role in brazing quality in automotive aluminum-based heat exchangers. Over the course of this research, NOCOLOK® flux consists of two phases of K2AlF5.H2O and KAlF4 with melting point around 580 °C was used. A flux slurry was applied on the base metal, and dried at 220, 300 and 380 °C in air. Mechanical assessment revealed that when flux dried at 300 °C, the joint withstands maximum shear stress of 44 MPa with complete bonding. At 220 °C and 380 °C, joint shear stresses are 34 MPa, 30 MPa respectively. 380 °C dry-off temperature under nitrogen gas improved shear strength to 39 MPa. Taking dry-off temperature as 300 °C the amount of defective heat exchangers was reduced from 6% to 2% on a daily basis.
 
Keywords: Brazing of Aluminum, NOCOLOK® Flux, Aluminum-Silicon
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Type of Study: Research | Subject: Manufacturing
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