At a glance
| Booth | X0016 |
| Country | GB |
| Website | www.cealloys.sandvik/en |
Company profile
Sandvik Osprey Ltd. manufactures Controlled Expansion Alloys, a range of high-modulus, low-density aluminium-silicon alloys with tailored thermal expansion. Components made from its CE alloys are typically used to provide support, protection and thermal management for devices and systems in demanding industries including semiconductors, electronics, space and automotive. Sandvik Osprey Ltd. provides tailor-made components in Osprey® controlled expansion alloys through a build-to-print process that covers material selection and design through finished components, supported by more than 160 years of materials expertise. Its build-to-print process enables custom-designed CE-alloy parts for a wide range of applications. Sandvik is an engineering group providing solutions for the manufacturing, mining and infrastructure industries with a focus on productivity, profitability and sustainability, and it applies engineering and innovation to the shift toward more sustainable business.
Exhibits
Osprey® controlled expansion alloys consist mainly of binary hyper-eutectic silicon-aluminium alloys rather than AlSiC composites; increasing silicon content lowers expansion coefficients and increases specific stiffness, and the alloys are suitable for components exposed to extreme temperature variations. The CE-alloy range is used for structural products, wafers and thermal-management products, and its high modulus and specific stiffness support stiff structural applications. The build-to-print process supports CE-alloy selection based on a wide range of mechanical and thermal properties and allows guided or collaborative solution development according to application requirements and priorities. CE alloys in the portfolio contain 27% to 87% silicon, and design feedback is available to improve manufacturability when selecting and designing components. For CNC and EDM manufacturing, the CE-alloys team uses Sandvik's special-alloy and metal-cutting expertise to develop specialist tooling and processes, operates a fully equipped machine shop at its UK facility, and works with approved subcontractors for global manufacturing solutions. Specialist operations include electrical feedthroughs for packaging applications, diffusion bonding for applications requiring internal cooling channels, and cutting and polishing processes for optical applications, with collaborative supply-chain development for projects. Available finishes and coatings include electroless plating, conversion coatings and light-absorbing coatings selected according to alloy and application. Main CE-alloy characteristics include controlled thermal expansivity of 5 to 17 ppm/°C, thermal conductivity of 120 to 180 W/m K, specific stiffness of 39 to 54 x10^3 Nm/g, and machinability, plateability and weldability. In the CE designation system, CE means Controlled Expansion and the number after CE gives the room-temperature CTE in ppm/°C; CE17MF and CE13MF contain small additions of Fe, Mn and Mg so that heat treatment similar to 6000-series Al-Si-Mg alloys hardens the matrix, improving machinability and potentially strength at the expense of thermal conductivity. The standard range includes CE17F with CTE 17 ppm/°C and Al/Si 73/27, CE17MF with 17 and 73/27, CE15F with 15 and 65/35, CE13F with 13 and 58/42, CE11F with 11 and 50/50, CE9F with 9 and 40/60, CE8F with 8 and 35/65, CE7F with 7 and 30/70, CE6F with 6 and 20/80, and CE5F with 5 and 13/87. For CE17F, CE17MF, CE13F, CE11F, CE9F, CE7F and CE6F respectively, compositions are Al-27%Si, Al-27%Si, Al-42%Si, Al-50%Si, Si-40%Al, Si-30%Al and Si-20%Al; typical ultimate tensile strengths are ≥160, 175-312 depending on heat-treatment condition, 205, 193, 181, ≥100 and N/A MPa; and yield strengths are 100, 282, 147, 189, -, - and N/A MPa. For the same grades, three-point bend strengths are -, -, 300, 300, 300, 270 and 319 MPa; Young's moduli are 91.8, 91.8, 101.9, 121.4, 118, 129.2 and 130 GPa; rigidity moduli are 35.8, 35.8, 42.2, 48.6, 46, 51.6 and N/A GPa; and Poisson's ratios are 0.28, 0.28, 0.27, 0.29, 0.29, 0.26 and N/A. Densities for CE17F, CE17MF, CE13F, CE11F, CE9F, CE7F and CE6F are 2.6, 2.6, 2.55, 2.51, 2.47, 2.43 and 2.35 g/cc, while hardness values are 60, 75-132 depending on heat-treatment condition, 90, -, 230, - and N/A HV. Room-temperature CTE values for CE17F, CE17MF, CE13F, CE11F, CE9F and CE7F are 15.3, 15.3, 12.2, 11.4, 9.1 and 7.2 ppm/ºC; over 25 to 200ºC they are 17.1, 17.1, 13.7, 12.3, 10.2 and 8.3; over 25 to 300ºC they are 18.1, 18.1, 14.6, 12.9, 10.9 and 8.8; over 25 to 400ºC they are 18.7, 18.7, 15.2, 13.4, 11.3 and 9.2; and over 25 to 500ºC they are 19, 19, 15.5, 13.7, 11.4 and 9.7. Additional CTE values include CE11F at 7.8 ppm/ºC over 100K to 200K, 10.6 over 200K to 300K, 9.2 over 100K to 300K and 11.6 over -60 to 200ºC, plus CE7F at 7.6 over -60 to 200ºC. At 25ºC, thermal conductivity values for CE17F, CE17MF, CE13F, CE11F, CE9F and CE7F are 177.4, 146.8, 145, 132, 121 and 120 W/m.K respectively; CE7F is listed at 180 at -100ºC, 140 at -50ºC, 135 at 0ºC, 110 at 50ºC, 110 at 100ºC, 100 at 200ºC, 88 at 300ºC, 80 at 400ºC and 75 at 500ºC. Other thermal-conductivity values are CE9F at 129 W/m.K at -50ºC, 125 at 100ºC, 108 at 200ºC, 98 at 300ºC, 90 at 400ºC and 85 at 500ºC, plus CE17F at 151.2 and CE17MF at 146.5 W/m.K at 200ºC; specific-heat values for CE17F, CE17MF, CE13F, CE11F, CE9F and CE7F are 846.3, 767.25, 857, 754, 780 and 785 J/kgºC. In the molten state Si and Al are mutually soluble, while rapidly solidified material has minimal Si solubility in Al below 0.3% and even less Al solubility in Si, so the products are true alloys rather than metal-matrix composites because all phases originate from a homogeneous melt. The Al phase is continuous up to about 85% Al, while above approximately 40% Si the Si phase also becomes continuous to form a co-continuous duplex alloy. A continuous Si phase produces stiffness with low thermal expansion and low internal stress, while a continuous Al phase enhances thermal conductivity and toughness and lowers electrical resistance. As Al content increases, electrical conductivity, thermal conductivity, strength, toughness, CTE and machinability increase, so the recommended approach is to select the highest Al content acceptable for the application. Sandvik can supply machined components with Si contents as high as 85% Si, including CE5F, but its relative brittleness can favor lower-Si alloys when exact expansion matching can be compromised; Kovar® packages with a CTE of about 7 ppm/°C have been replaced successfully with CE9F, CE11F and CE13F.
Capabilities and products
- controlled-expansion aluminium-silicon alloy manufacturing
- build-to-print custom CE-alloy components
- CNC/EDM machining of CE alloys
- electrical feedthrough fabrication for packaging
- diffusion bonding for internal cooling channels
- electroless plating for CE alloys
- conversion coatings for CE alloys
- light-absorbing coatings for CE alloys
- optical cutting and polishing of CE alloys
- CE-alloy material selection and design feedback