Metallic Substrate Vs Ceramic Honeycomb

Pressure drop difference between substrates of different lengths in a substrate typical honeycomb channels have a hydraulic diameter to length ratio of 1 100.

Metallic substrate vs ceramic honeycomb.

Other channel cross sections are possible including triangular hexagonal trapezoidal and round. The principal advantage of the metallic honeycomb is the thin wall of the metal monolith relative to the ceramic extrusions which results in lower pressure drop than is typically available with ceramic supports. It holds up to long heat cycles but doesn t handle vibration well. The material of the honeycomb ceramic substrate is isotropic linear elastic and the behavior is within small deflection linear theory limits.

Extensive heat cycles impact damage and such take a toll on ceramic more then they do on metallic. Metal catalysts use a thin metal foil which creates the honeycomb. In sizes larger than 6 od metallic substrates are competitive with ceramic and sizes larger than 10 metallic s have a lower cost. Typically the ceramic converters are used on obdii vehicles.

The computations are thus tremendous and costly. In small sizes under 6 od the ceramic is usually more cost effective per piece over the metallic but due to difficulty in packaging ceramic and extra processes required the metallic total system cost often is more advantageous. Over the years we have formed metals to all thicknesses. In performing calculations if each channel is represented by a 10 10 100 cell modeling all the channels produces millions of cells.

Now we work with many customers to design and manufacture substrates in all shapes and forms to meet emissions compliance needs among many other. Metallic substrates corrugated and honeycomb. In the first type of technology honeycombs are fabricated using uncoated foil. Off the top of my head ceramic substrates tend to be more fragile then metallic.

A parametric finite element model of the substrate is shown in figure 3 2 and was developed considering the following assumptions. Ceramic has long been used the build the catalyst. Ceramic catalysts are always padded by a layer of heat resistant padding between the shell and the honeycomb. The ceramic catalytic converters such as part mf99659hm are not as strong and usually do not last as long as metallic substrate converters.

Htg began by forming metallic honeycomb substrates for jet engines in the early 1980s. Catalyst coated foil substrates. Once the ceramic cracks it tends to break apart. Based on the catalyst application method metallic substrates are divided into two types.

The modulus of elasticity is e 4800 mpa and. Plus depending on the manufacturing process ceramics tend to have thicker cell walls then metallic. The advantage of ceramic though is it tends to be cheaper.