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Views: 0 Author: Site Editor Publish Time: 2025-06-05 Origin: Site
In hydraulic brake systems, the fluid comes into continuous contact with various metal alloys—steel, copper, brass, and cast iron. Over time, brake fluid impurities and moisture accelerate metal corrosion, leading to seal failures or abrasive particles in caliper bores. The Brake Fluid Metal Test Piece Corrosion Tester from Changsha Friend Experimental Analysis Instrument Co., Ltd. quantitatively evaluates brake fluid-induced corrosion on defined metal specimens, ensuring that fluids meet rigorous compatibility standards.
Brake fluid specifications (such as ISO 4925 and SAE J1703) mandate strict limits on corrosive action. Even trace acids formed by brake fluid degradation can attack metal surfaces, compromising hydraulic integrity. By measuring corrosion rates under accelerated conditions, laboratories can:
Confirm that new fluid formulations do not exceed allowable metal loss.
Detect impurities or degraded additives that exacerbate corrosion.
Guide periodic fluid replacement schedules in maintenance programs.
Verify additive efficacy (e.g., inhibitors, buffers) under high-temperature exposure.
The tester supports a modified ASTM D4359 protocol, which involves:
Coupon Preparation
Standard metal test pieces (e.g., cast iron, copper, C17200 brass) are prepared to specific dimensions (approximately 10 mm × 50 mm × 1 mm).
Surfaces are polished to a mirror finish (Ra < 0.1 µm) and degreased in solvent.
Immersion Test
Coupons are suspended in sealed containers filled with test fluid, the container purged with dry nitrogen to minimize oxidation.
The assembly is placed in a controlled-temperature oven at 100 °C for 168 hours.
Optional agitation (rotational wheel or orbital shaker at 20–30 rpm) ensures uniform fluid contact.
Post-Test Analysis
Coupons are cleaned in inhibited acid solution to remove deposits without attacking base metal.
After rinsing and drying, mass loss is determined on a precision balance (±0.1 mg).
Corrosion rate is expressed as mg/cm² for each metal type.
Temperature-Regulated Oven: Maintains 100 °C ±0.5 °C for extended durations.
Nitrogen Purge System: Minimizes oxidative corrosion that could confound results.
Agitation Fixture: Provides programmable motion (e.g., reciprocating or rotating) to simulate in-service fluid dynamics.
Integrated Data Logger: Tracks temperature, fluid pH (if a probe is installed), and elapsed time; exports CSV reports.
Modular Coupon Holders: Accommodate multiple metal types in one run, ensuring parallel comparison across alloys.
Brake Fluid R&D Laboratories: Screen candidate formulations for compatibility with common brake-system alloys.
Automotive OEM Certification: Demonstrate that fluids meet industry corrosion thresholds before vehicle integration.
Aftermarket Fluid Suppliers: Validate additive packages after manufacturing scale-up to ensure no cross-contamination.
Independent Test Houses: Provide third-party validation for fluid performance claims in warranty or safety audits.
Coupon Handling: Use powder-free gloves and non-saline tools to avoid fingerprint oils or chloride contamination.
Fluid Preparation: Fill test containers under low-humidity conditions (< 10 % RH) to limit water uptake before test initiation.
Cleaning Protocol: Employ the specified acid composition and dwell time to remove corrosion products without metal loss, then rinse with deionized water and bake at 60 °C for 1 hour.
Duplicate Runs: Test each metal type in triplicate to establish statistical confidence; discard outliers and report averages.
Baseline Reference: Include a known reference brake fluid in every batch to confirm instrument and method consistency.
By using the Brake Fluid Metal Test Piece Corrosion Tester, formulators and service providers can ensure that brake fluids maintain long-term compatibility with metal components, supporting safe, reliable braking performance.
