Understanding corrosion in your PC cooling system

Understanding corrosion in your PC cooling system

In a more dominating PC water-cooling world, liquid coolants are becoming dynamic forces to achieve incredible performance for gaming applications dissipating heat faster, regulating operative temperatures, avoiding spikes and protecting interacting parts from overheating compared with forced air cooling.

Water-cooling related problems

Water is the best and cheapest PC coolant due to its excellent thermal properties. The reality is that water interacts with metal parts in contact, promoting corrosion and can host microorganisms' growth leading to fouling and scaling issues. Therefore, to avoid costly damage to your cooling system and other components, a fully formulated PC coolant specifically designed for the rigours of extended use is highly recommended. Avoiding corrosion is critical.

What is corrosion?

Corrosion is a thermodynamically favourable process changing from metal status to more-stable oxide forms through chemical, electro-chemical or abrasive reactions. These changes modify the appearances and capabilities of materials to efficiently transfer heat, damaging surfaces with the creation of hot spots, rust and erosion.

There are different types of corrosion, but the main ones affecting the closed-loops of computers are:

  • pitting corrosion, due to the use of water containing high quantities of chlorides, predominantly localised in stagnant areas where the flow is low, particularly in the presence of oxygen;
  • galvanic corrosion occurs between two metals electrically connected through a conductive media like water leading to permanent damage to the metal surfaces;
  • erosion corrosion due to pigments' sedimentation or the formation of precipitates from coolant reactions with poor-quality water or mixing with different fluids.

Preventing Corrosion

Although in different ways, all the computer metal parts exposed to cooling solutions are vulnerable to corrosion in every environment. Therefore corrosion inhibitors must be added to the coolants' formulation. Indeed, inhibitors, although present in small quantities, act as a buffer and de-scaling agent, maintaining the pH of the coolant at safe levels and interacting with metal surfaces forming protective layers. Unfortunately, these inhibitors do not last forever but deplete their levels over time. Average computer coolant operative life is 2-3 years, if well maintained.

How is the corrosion resistance of the inhibitor packages tested?

The effectiveness of inhibitors packages is assessed through corrosion tests under harsher conditions than normal use, including high temperatures and the presence of salts in the solution. This prevents instability issues and optimises the dose of inhibitors and microbial agents.

Go Chiller Astro D-Series heat transfer fluids for gaming applications are tested against the ASTM D 1384 method for engine coolants as a corrosion benchmark. In this method, copper, aluminium, iron, brass, solder and steel specimens (see below) are immersed in a continuously aerated cooling solution, dosed with corrosive water containing 100 ppm each of sulphate, chloride and bicarbonate, heated to 88°C for two weeks. The average weight change incurred by the specimens determines the pass evaluation.

As reported in the Table below, Astro D-series coolants pass this test ensuring integrity and metal protection of the whole cooling system.

Metals Average Weight Loss
(mg/specimen)​
Limit
(mg/specimen)
Status
Copper 0.4 10 Pass
Brass 0.2 10 Pass
Stainless Steel 0.2 10 Pass
Cast Aluminium 1.8 30 Pass
Cast Iron 0.2 10 Pass
Solder 0.4 30 Pass

Appearance: The metal conditions appear to be good in good conditions. No sign of corrosion has been detected.

Before test

Corrosion testing metals before

After test

Corrosion testing metals after

What distinguishes Astro D-series coolants from the competitors?

Not all the competitors invest money in testing gaming fluids under extreme automotive conditions. Differently, Flexegraph created custom-built fluids meeting ASTM D 1384 requirements and, hence, able to resist all the possible types of corrosion in every situation, and if well maintained, extends the lifetime of computer components. To create customers' confidence and trust, all the coolants' fundamental aspects, properties, instructions to use, and corrosion results are transparent and summarised in detail in our product data sheets.


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