Comparison between CE alloys and competitive materials

Osprey™ CE alloys offer many advantages compared to most competitive materials. For example, CE alloys are lighter than competitive materials, such as:

Aluminium alloys
Aluminium silicon carbide (AlSiC)
Iron nickel alloys (e.g. Kovar^*, Alloy 49, F15)
Titanium (Ti)
Copper-molybdenum (Cu-Mo)
Copper-tungsten (Cu-W)
Steels

CE alloys also have controlled expansion coefficients at any preselected value in the range 5 to 17 ppm/°C.

The tables shows comparisons of CE alloys with other thermal management and packaging materials in terms of, for example, density, coefficient of thermal expansion, thermal conductivity and specific stiffness.

CE alloy advantages over competitive materials
Competitive materials	Osprey™ CE alloys
Copper-85% tungsten (CuW)	CE7 uses significantly lower cost raw materials and is 1/6 the density.
Copper-85% molybdenum (CuMo)	CE7 uses significantly lower cost raw materials and is 1/4 the density.
Kovar^* (FeNiCo)	CE7 and CE9 housings are comparable in price but are 1/3 the density and have 6–9 x thermal conductivity, eliminating the need for heat sinks. CE7/9 do not normally require heat treating and do not burr.
Aluminium- silicon-carbide (AlSiC)	CE7 and CE9 do not require mould tools, thus prototypes can be delivered quickly and with much lower setting-up costs. CE7/9 are readily machinable and plateable.
Beryllium-beryllium oxide (Be-BeO)	CE alloys are environmentally friendly and non-toxic.
Titanium	CE9 or CE11 are 1/2 the density and have 6x the thermal conductivity.
Aluminium alloys (e.g. 6061)	CE17 is 5% lighter, 30% stiffer and has a lower CTE than 6061 Al alloy, similar to many laminate board materials (e.g. FR4). CE17 is also less prone to burring.
Copper	CE17 is 1/4 the weight, stronger and easier to machine.
Steel	CE13/11 have similar CTEs but are 1/3 the density.

Density

Osprey™ CE alloys are practically the lowest density, controlled expansion alloys commercially available and offer substantial weight advantages over most other regularly used materials such as CuW, CuMo, Kovar^*, Ti, AlSiC and Al alloys.
Mechanical properties for CE alloys

Coefficient of thermal expansion

Osprey™ CE alloys exhibit a range of CTEs depending on Al and Si content. For example, CE7 (70% Si) matches the CTE of alumina, LTCC and GaAs; whilst CE17 (27% Si) matches the CTE of Cu and several laminate board materials.
Thermal properties for CE alloys

Thermal conductivity

Osprey™ CE alloys have much higher thermal conductivities than titanium and Kovar^* and, therefore, housings can be manufactured without the need to include heat sinks.
Thermal properties for CE alloys

Specific stiffness

The high specific stiffness of controlled expansion alloys such as CE7 enables products to remain extremely flat during thermal cycling.
Mechanical properties for CE alloys

Alloy	CTE, ppm/ºC	Thermal, W/mK	Density, g/cc	Modulus, GPa	Yield, MPa
Al6061	22.6	210	2.7	70	140
Copper	16	385	8.9	110	33
CE17	16.0	150	2.6	92	150
Steel	12.2	52	7.8	200	180
Titanium	8.9	17	4.5	116	140
CE11	11.0	150	2.55	110	150
Cu-4CuMo-Cu	8.0–10.0	170	10.0	195	630
Al graphite	7.5/23	190	2.5	89	160
CE7	7.2	120	2.5	125	110
Al SiC	6.8	170	3.0	290	450
Cu 85% W	6.8	180	16.4	360	1150
Cu 85% Mo	6.8	165	10.0	310	1000
Kovar	6.0	15	8.4	131	345
Molybdenum	5.2	140	10.2	330	415

Alloy	Plateability	Machine	Welding	Forming
Al6061	Good	Good	Good	Good
Copper	Good	Good	Good	Good
CE17	Good	Good	Good	Good
Steel	Good	Good	Good	Good
Titanium	Fair	Fair	Fair	Good
CE11	Good	Good	Good	Poor
Cu-4CuMo-Cu	Fair	Poor	Poor	Fair
Al graphite	Poor	Good	Poor	Good
CE7	Good	Fair	Poor	Poor
Al SiC	Poor	Poor	Poor	Poor
Cu 85% W	Fair	Fair	Poor	Poor
Cu 85% Mo	Fair	Fair	Poor	Poor
Kovar	Good	Good	Good	Good
Molybdenum	Fair	Poor	Poor	Poor

* Kovar is a trademark of Carpenter Technology Corporation.