SUPERIOR FLUX MFG CO ENVIRONMENTALLY SAFE BRAZING FLUXES
SUPERIOR FLUX & MFG. CO.
ENVIRONMENTALLY SAFE BRAZING FLUXES DR. Y. BASKIN SUPERIOR FLUX & MFG. CO. INTERNATIONAL BRAZING & SOLDERING CONFERENCE FEBRUARY 18, 2003 SAN DIEGO, CA
MOTIVATION FOR SAFER FLUX DEVELOPMENT v Cleaner effluents v Better workplace air quality v Improved health and safety in brazing operations
ELIMINATION OF HAZARDOUS CHEMICALS AND METALS v v v Cadmium from Brazing Filler Metals Lead from Plumbing Soft-Solders CFC Solvents from All Applications Hydrazine from Industrial Applications Asbestos from Insulation
COMMON BRAZING FLUX CHEMICALS v v v Boric Acid Boron Oxide Elemental Boron Potassium Bifluoride Potassium Fluoride Potassium Pentaborate Potassium Tetraborate v Silicon Dioxide v Sodium Tetraborate (Borax) v Wetting Agents v
KBF BRAZING FLUX DIAGRAM
HAZARDS ASSOCIATED WITH GENERAL-PURPOSE FLUXES v Working with raw flux v Brazing at elevated temperatures when HF and BF 3 gases are released v Discharging raw flux and flux residues into plant effluent, and entry into water system
EXPOSURE LIMITS AND HAZARD LABELS FLUORINE COMPOUND ACGIH OSHA TWA-TLV TWA-PEL NIOSH TWA-REL OSHA Label D. O. T. Label Boron Trifluoride 1 ppm - Poison Hydrogen Fluoride 3 ppm Toxic Corrosive Potassium Bifluoride 2– 5 mg/m 3 Toxic Corrosive Potassium Fluoborate 2– 5 mg/m 3 Toxic - Potassium Fluoride 2– 5 mg/m 3 Toxic -
POTENTIAL HEALTH ISSUES FROM FLUORIDE-BEARING FLUX v Irritation to skin and fingernails by the raw flux. v Irritation of the eyes, mucous membranes, and respiratory system by gases and fumes generated during brazing. v Calcium depletion (sclerosis) of the bones, and mottled teeth from long-term exposure to fluoride gases and fine-fume particles. v Potential health hazards from discharge of untreated flux and flux residues into water supply.
PHYSICAL PROPERTIES OF SILVERBRAZING FLUX WITHOUT POTASSIUM BIFLUORIDE* Form: Color: Specific Gravity: Water Content: Viscosity @ 22 C/72 F: Fluorine Content: Flash Point: Freezing Effects: Heating Effects to 50 C / 122 F: Activity Temperature Range: Creamy Paste Off White 1. 5 Less than 35% 140, 000± 14, 000 Centipoises 18. 0% None 485– 870 C / 900 -1600 F * not boron-modified
PHYSICAL PROPERTIES OF FLUORIDE-FREE SILVERBRAZING FLUX Form: Color: Specific Gravity: Viscosity @ 22 C/ 72 F: Fluoride Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Creamy Paste White 1. 4 225, 000 ± 20, 000 Centipoises Less than 50 ppm None Minimal 670 -870 C / 1235 -1600 F
TEMPERATURE RANGES FOR FLUXES AND FILLER METALS Flux Activation Temperature Recommended Maximum Temperature Average Fluoride-Bearing 570 C / 1050 F 870 C / 1600 F Fluoride-Free 670 C / 1240 F 870 C / 1600 F Filler Alloy Liquidus Temperature Recommended Maximum Temperature BAg-28 (40% Ag) 710 C / 1315 F 802 C / 1475 F BAg-36 (45% Ag) 688 C / 1270 F 785 C / 1450 F BCu. P-4 (6% Ag) 718 C / 1325 F 785 C / 1450 F
FILLER METAL SPREAD AS A FUNCTION OF BASE METAL, FILLER ALLOY, AND FLUX BASE METAL FILLER ALLOYS BAg-36 FLUX BAg-28 Brass Fluoride-Free Fluoride-Bearing Excellent Excellent Copper Fluoride-Free Fluoride-Bearing Moderate Excellent Moderate Poor Mild Steel Fluoride-Free Fluoride-Bearing Moderate Poor Furnace Temperature: 785 C/1450 F Excellent Spread: >2. 0 cm 2 Poor Spread: <0. 5 cm 2 BCu. P-4 Time in Furnace: 60 Seconds Moderate Spread: >0. 5 cm 2<2. 0 cm 2
PHYSICAL PROPERTIES OF HIGH TEMPERATURE FLUX WITHOUT POTASSIUM BIFLUORIDE Form: Color: Specific Gravity: Water Content: Viscosity @ 22 C / 72 F: Fluorine Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Creamy Paste Dark Brown 1. 7 Less than 30% 200, 000 ± 20, 000 Centipoises 3% or Lower None 760 - 1205 C / 1400 - 2200 F
PHYSICAL PROPERTIES OF FLUORIDE -FREE HIGH TEMPERATURE BRAZING POWDER FLUX Form: Color: Specific Gravity: Fluorine Content: Volatile Content: Flash Point: Freezing Effects: Heating Effects to 50 C/122 F: Activity Temperature Range: Powder White 1. 5 (Average) Less than 50 ppm <0. 1% None 760– 1205 C/1400 -2200 F
BASE METAL, AND FILLER METAL RELATIONSHIPS Flux Category Silver Brazing without Potassium Bifluoride Base Metals Copper and Copper-based Alloys, Ferrous Alloys Stainless Steel Filler Metals All (BAg) Alloys Phos-Copper (BCu. P) Alloys Silver Brazing Fluoride-Free Copper and Copper-based Alloys, Select Ferrous Alloys Cd-Free BAg Alloys Phos-Copper BCu. P Alloys High Temperature Brazing without Potassium Bifluoride Ferrous Alloys, Carbides CDA 681, CDA 773; Manganese containing Nickel Alloys High Temperature Brazing, Fluoride-Free Ferrous Alloys, Carbides CDA 681, CDA 773; Manganese containing Nickel Alloys
PRIMARY SKIN IRRITATION STUDY OF SILVER BRAZING FLUXES FLUX WITHOUT POTASSIUM BIFLUORIDE PRIMARY DERMAL IRRITATION INDEX (PDII) 1. 5 CLASSIFICATION Not a primary irritant. Noncorrosive to skin. FLUORIDE-FREE FLUX 2. 3 Not a primary irritant. Noncorrosive to skin. POTASSIUM BIFLUORIDE FLUX 5. 9 A primary irritant. Corrosive to skin. * The Non-Corrosive/Corrosive dividing measurement is 5. 0. The Draize scoring system is used for defining the skin irritation levels.
BENEFITS OF USING FLUORIDE-FREE FLUX v Addresses workplace safety by reducing toxic emissions v Addresses the long-time issue of skin and fingernail irritation v Substantially reduces the fluoride effluent emission in local and regional waterways v Complements the Cadmium-Free workplace with much safer fluxes
SUPERIOR MANUFACTURES QUALITY FLUXES. OUR BUSINESS IS SOLVING PROBLEMS
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