Summary

Thermal contact conductance is required to evaluate heat transfer through the interface of two materials and is dependent on a range of material and interface properties. This article provides a brief summary of these properties and a list of thermal contact conductance for a selection of metal-metal pairs.



Definitions

: Thermal contact conductance (W/m2.°C)

Introduction

Thermal contact conductance is the thermal conductivity of the interface between two contacting surfaces and is dependent on the surface roughness, material properties, interface temperature and interface pressure.

Thermal contact conductance is typically determined by measuring the heat flux and temperature change across the interface of two materials while simultaneously maintaining a constant load (pressure) on the two materials. However characterisation of the thermal contact conductance in industrial settings can be difficult as when two materials are fastened together by bolts, screws of rivets the pressure profile at the interface is often non-uniform.



Thermal Contact Conductance Data

Below are some values for the thermal contact conductance of a selection of metal-metal pairs.

MaterialRoughness (μm)Temperature (K)Pressure (atm)hc (W/m2.°C)
Stainless steel 416 -
Stainless steel 416
2.54 (Ground)90-2000.3-2.53800
Stainless steel 304 –
Stainless steel 304
1.14 (Ground)204 – 71900
Aluminium –
Aluminium
2.54 (Ground)1501.2-2.511,400
Copper -
Copper
1.27 (Ground)201.2-20143,000
Copper -
Copper
3.81 (Milled)201-555,500
Stainless steel -
Aluminium
20-30

1.0-2.0
2010
20
10
20
2900
3600
16,400
20,800
Steel Ct-30 –
Aluminium
1.4-2.0 (Ground)

4.5-7.2 (Milled)
2010
15-35
10
30
50,000
59,000
4800
8300
Aluminium -
Copper
1.3-1.4 (Ground)
4.4-4.5 (Milled)
205
15
10
20-30
42,000
56,000
12,000
22,000