EMI Shielding Stainless Steel Honeycomb Core HEMP Hardening

Product Specification

Stainless Steel Honeycomb Core Spot Welded for HEMP Hardening is a conventionally welded metal honeycomb core. This electromagnetic pulse, referred to as HEMP E1, is characterized by double exponential shaped E-field pulse with amplitude of 50 kV/m at the worst-case location on the ground and rise time on the order of a few nano-seconds. EMP E1 couples through the air to conductive objects such as overhead conductors, control cables, communication cables, and so on and can expose connected devices to voltage and current transients. The E-field can also radiate devices directly and induce voltage and current surges within the device. This coupling process generates voltage and current surges which can disrupt or damage sensitive electronic equipment such as digital protective relays, supervisory control and data acquisition (SCADA) systems, and communication systems.

Specifications

Properties

Welded honeycomb core, no matter what material is, such as aluminum, stainless steel, steel, titanium etc, possesses better mechanical properties against regularly produced glued honeycomb core. So it performs significantly better again the common honeycomb bonded by adhesive on strength, modulus, corrosion resistance, dimensional stability etc. However, generally, these critical performance variables should be evaluated: material, airflow and attenuation.

1. Material Composition

Stainless steel grade should be considered according to the real application. Custom materials other than stainless steel are available upon request. Here are the parameters need to be evaluated:

Durability

Material type and grade is the first aspect to be evaluated then plating, discussed in depth later, can improve durability.

Weight

Material, structure and thickness of the material can affect the total part weight.

2. Corrosion resistance

Typically brass and stainless steel should be used in slashing environments. Plating or nonconductive surface coatings can improve corrosion resistance for all honeycomb types.

3. Shielding Performance

Different honeycomb core material offerings have different electrical performance, due to both inherent base material properties as well as the differing manufacturing processes used during honeycomb forming. Therefore, different EMI shielding performance may be realized. Shielding performance for different materials is ranked as brass, aluminum, steel and stainless steel. Plating can improve honeycomb shielding.

Specific attenuation requirements can be met through either plated or unplated alloys. Plating adds cost to the final product vent. Plating process for improving shielding is ranked as nickel, tin, tin-lead and zinc.

4. Airflow & Attenuation

Airflow and attenuation are inversely proportional. Infinitely large honeycomb cells result in infinitely small attenuation (and vice versa). Typically, as a design baseline, airflow performance requirements are calculated to meet thermal performance needs for the assembly that the vent is to be installed onto. Once airflow is determined, attenuation and other requirements can be evaluated. Standard cell sizes for honeycomb are 1/16", 1/8" and 1/4", with 1/8" being most common. Standard thicknesses are 1/4," 1/2" and 1," with 1/4" being most common.