Overview
Paste brazing material is a ready-to-use formulation combining metal alloy powders with flux in a viscous medium. Developed as an alternative to solid brazing rods, these pastes enable precise application in complex joint geometries. The technology gained prominence in the 1980s with advancements in flux chemistry and particle size control. Modern formulations typically contain silver-copper-zinc alloys (Ag-Cu-Zn) with proprietary flux systems. Automotive manufacturers account for approximately 40% of global consumption, particularly for heat exchanger production. The paste format eliminates pre-cleaning steps in many applications due to integrated flux activation.
Physical and Chemical Properties
Brazing pastes exhibit thixotropic behavior - maintaining shape when undisturbed but flowing under shear stress during application. Viscosity ranges from 50,000-200,000 cP at 25°C, engineered for screen printing or syringe dispensing. The metal alloy fraction constitutes 60-85% of total weight, with particle sizes between 10-45μm for optimal melting characteristics. Flux components typically include potassium fluoborate compounds (KBF₄) for oxide removal, with melting points deliberately lower than the base alloy. Thermal analysis shows endothermic flux activation at 300-400°C followed by alloy liquidus formation. Residue pH post-brazing averages 3.5-5.0, requiring neutralization in critical applications.
Main Applications
HVAC system manufacturers utilize brazing pastes for copper-aluminum joints in evaporator coils, where conventional methods risk galvanic corrosion. The paste's localized application prevents flux contamination of sensitive areas. Automotive applications focus on aluminum charge air coolers, with paste formulations specifically developed for 3003/4343 aluminum alloys. In electronics, high-silver content pastes (Ag >50%) create vacuum-tight seals in hermetic compressors. The medical device industry employs biocompatible variants for stainless steel instrument assembly. Emerging applications include photovoltaic cell interconnects and aerospace heat shields, where paste dispensing enables automated precision unattainable with manual brazing rods.
Safety and Storage
Brazing paste containers require explosion-proof storage due to potential hydrogen gas generation from flux hydrolysis. OSHA mandates local exhaust ventilation during application to maintain fluoride exposure below 2.5mg/m³ (8-hour TWA). Thermal decomposition products include zinc oxide fumes requiring P100 filtration. Unopened containers maintain stability for 12-18 months at 25°C with <60% humidity. Once opened, paste should be used within 3 months to prevent solvent evaporation and flux degradation. Spent containers must be rinsed with 5% sodium bicarbonate solution before disposal to neutralize residual fluorides.
B2B Procurement Guide
Industrial buyers should specify three critical parameters: alloy composition (AWS A5.8 classification), flux type (FB3-C for corrosive environments), and viscosity range (ASTM D2196 method B). For high-volume applications, request rheology data to confirm pumpability in automated systems. Quality verification should include metallographic analysis of test joints for porosity (<5% by ASTM E562) and tensile strength testing. Consider supplier capabilities for custom particle size distributions when brazing thin materials (<0.5mm). Bulk purchases (50kg+) typically attract 15-20% discounts, but verify shelf life commitments for inventory planning.
Related Manufacturers
- 主营：磷合金焊条、银铜合金焊条、银铜合金焊环、真空炉铜钎料膏、锌锰镍合金焊环、锌锰镍合金焊条
- 主营：各类金属粉末、不锈钢粉末、3d打印粉末、粉末冶金材料、MiM材料、钎焊料、激光熔覆材料、喷涂粉末、催化剂
- 主营：纯铜粉、纯银粉、纯镍粉、钎焊工、钎焊粉、钎焊膏、银焊膏、纳米棒、纯钛粉、磁合金、锌合金、铝合金、钼合金、基粉末、镍合金、磁粉芯、合金粉、铁硅铝、铜焊粉、金刚石、模具钢、钛合金、金属粉、球形镍粉、金属铬粉
- 主营：井式炉、箱式炉、退火炉、台车炉、高温推车炉、工业炉、工业电炉、燃气炉、回火炉、罩式炉、快速淬火炉、钛合金烧结炉、滚筒炉、铝合金淬火炉、电缆退火炉、地坑炉、玻璃烧结炉、推杆炉、氮化炉、高效退火炉、热处理推杆炉、热处理炉、高精度井式炉、台车式电阻炉、电阻炉
- 主营：耐磨焊条、耐磨焊丝、不锈钢焊条、钎焊焊接材料、不锈钢焊丝、铜焊条、铜焊丝、铝焊丝、铝焊条、镍基焊条、镍基焊丝、银焊条、银焊片、钴基焊条、钴基焊丝、耐热钢焊条、耐热钢焊丝、模具焊条、模具焊丝
- 主营：真空高温炉、真空烧结炉、真空气氛炉、真空钎焊炉、正负极材料气氛炉、箱式炉、钠电锂电箱式炉、高温炉、管式炉、升降炉
- 主营：真空热压炉、真空电弧炉、真空碳管炉、真空钎焊炉、真空感应炉、真空退火炉、甩带炉、真空感应熔炼炉、甩带机、真空重熔炉、石墨烧结炉、真空熔炼炉、电弧熔炼炉、真空烧结炉、气氛炉、真空蒸馏炉、晶体炉、仪器设备、感应线圈、区域熔炼炉、真空悬浮炉
- 主营：马弗炉、牙科炉、升降炉、耐火材料、台车炉、电阻炉、梯度炉、气氛炉、回转炉、管式炉、防爆锁链、工业烘箱、物料处理、高温电炉、智能控温、工业电炉、多层保温、显示仪表、陶瓷电炉、精钊机械、加热设备、实验电炉、井式真空炉、真空加热炉、实验室器皿
- 主营：钎焊炉、回转式焙烧窑
- 主营：耐磨涂层、陶瓷喷涂、喷涂碳化钨、粉末冶金材料、耐磨合金刀片、防腐纳米涂层
- 主营：纯铜粉、纯镍粉、纯铬粉、碳化钨、钒铁粉、紫铜粉、钛铁粉、金属钨、钨粉纯、石墨粉、黄铜粉、合金粉、钼铁粉、青铜粉、纯铅粉、球形镍粉、纳米铅粉、电解锡粉、导电镍粉、铬粉用户、激光熔覆、铜粉需要、纳米铜粉、超细钴粉、铜粉预定
- 主营：气氛回转炉、连续式回转炉、连续式回转窑、钎焊炉、间歇式回转炉、间歇式回转窑、活性炭蒸气活化炉、真空气氛炉、网带炉、氢气网带炉、气氛网带炉、气氛推板炉、推板窑、辊道炉、碳化炉、活化炉、管式炉、网带烧银炉、升降炉、台车炉、台车气氛炉、井式炉、烧结炉、地坑炉、隧道窑、还原炉
- 主营：导电银浆、导电银胶、金浆、导热材料、屏蔽材料、柔性电极材料、导热相变材料、导电橡胶、镀银导电布、金粉、铂电极浆料、FPC软板、镀金导电布、银钯浆料、电阻浆料、柔性电极
- 主营：福美钠、五氧化二钒、氨基磺酸、酵母膏、氨基化锂、焦性没食子酸、次氯酸钙、漂粉精、酪蛋白胨、甘油、九水硫化钠、牛油脂肪酸、氟硅酸钠、单乙醇胺、氢氧化钾、氟化钠、氟化钙、氧化铅、油酸钠、偏钒酸铵、氢氧化钡、EVA乳液、二硫化钼、氟化氢钾
- 主营：三甘醇、五氧化二钒、纯牛骨蛋白胨、牛油脂肪酸、氯偏乳液、苄基胂酸、漂粉精、苯甲醇、草酸镍、磷酸、六氟磷酸钾、次氯酸钙、钯碳、草酸钛钾、粘土固化剂、福美钠、戊二醛、碳酸钡、硝酸异辛酯、二甲基二硫代氨基甲酸、四氧化三铅、氯化锌、松醇油、磺化油、氟化氢钾
- 主营：c扫描、超声波探伤仪、超声测厚仪、相控阵探伤仪、TOFD探伤仪、绝缘子探伤仪
- 主营：冷却塔、助焊剂、焊接机、钎焊机、钎焊工、钎焊膏、焊接材料、钎焊辅料、钎焊材料、铜焊材料、合金钎焊料、铜焊片、合金焊料、焊接设备、加工工艺、堆焊设备、冷却设备、合金焊片、合金焊机、截齿加工、铜镍焊片、截齿焊片、处理生产线、刀圈堆焊机、焊接生产线