is it possible to use a few flat sheets of aluminum foil as a replacement for heat sink compound?? i have a very big copper heatsink and was wondering if aluminum foil would work?? any advice?
Absolutely not. Arctic Silver 5 is nice and cheap so use it.
The reason for thermal paste is to fill in micro ridges and pits in your heatsync and CPU, eliminating air pockets. AS5 is designed with micro bits of silver (~99% silver) that are able to fill in the pits and such for a more thorough thermal contact. Theoretically, you want as much of the CPU touching your heatsync with no thermal paste between them, only filling in the air pockets caused by the uneven surfaces.
Also note that for metals, copper and silver are the best for conducting heat (silver being the best). Aluminum is a poor conductor and usually only used in situations were you need less weight (copper is heavy). Whether foil will decrease or increase performance, I cant tell you. Is it better than thermal paste? Not even close.
Also note, thermal compounds usually need a cure time (AS5 usually takes 4-6 days to cure, droping up to 4C in temp from the original temp). Arctic Silver Ceramique works a lot better than Arctic Silver 5 in below freezing temperatures (for phase change cooling and N02) and also has a very short cure time.
Zalman USA CNPS10XEXTREME Copper/Aluminum CPU Cooler, Zalman Aluminum CPU Cooler Cooling Fan f. Intel 775 1156 AMD AM2 AM2+ AM3 Socket, Aluminum Cooling Block F CPU Graphics CO2 Laser Cooler Peltier Liquid cool SYS, Hyper 212 Plus CPU Cooler Socket 1155/1156/1366/775/AM3/AM2 Copper/Aluminum Reta, Aluminum DC CPU Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, Dynatron A6 Aluminum Copper Base Heatpipes cooler Fan PWM for AMD CPU Socket, CNPS10XEXTREME Copper/Aluminum CPU Cooler Zalman USA, PC Computer 3 Pin Heatsink CPU Aluminum Cooler Fan, Aluminum Plastic Heatsink Cooling Fan Cooler for CPU, Zalman CNPS10XEXTREME Copper/Aluminum CPU Cooler, Zalman USA CNPS10XEXTREME-Copper/Aluminum CPU Cooler - Kit, Zalman USA CNPS10XEXTREME-Copper/Aluminum CPU Cooler, Zalman CNPS10XEXTREME Copper/Aluminum CPU Cooler, Zalman CNPS10XEXTREME Copper/Aluminum CPU Cooler, Aluminum Plastic Heatsink Cooling Fan Cooler for CPU, INTEL GENUINE Pentium P4 Socket 478 Aluminum HeatSink with cooler CPU 100% WORKS, PC Computer 3 Pin Heatsink CPU Aluminum Cooler Fan, RR-H612-20PK-R1 CPU Cooler Hyper 612 PWM for Intel AMD Aluminum Heatpipe, RR-G524-18PK-R1 Fan GeminII S524 CPU COOLER for Intel AMD Copper Aluminum, RR-212E-20PK-R2 Fan Hyper 212 EVO CPU Cooler for Intel AMD Aluminum Heatpipe, K985 CPU Cooler 3U LGA1155-LGA1156 Aluminum Heatsink-Fan Retail, ETS-T40-TB Fan TB SILENCE CPU Cooler Side Flow for Intel AMD Copper Aluminum No, CNPS11X PERFORMA CPU Cooler AMD -Intel Aluminum Dual Heatsinks, CNPS10X OPTIMA CPU Cooler AMD -Intel Pure Copper-Aluminum, Zalman - CPU Cooler CNPS10X OPTIMA AMD Intel Pure Copper Aluminum Retail , Phenom / Athlon CPU Cooler, Socket AM2/AM2+, Copper/Aluminum, 125W, Athlon Dual Core CPU Cooler, Socket AM2/AM2+, Copper/Aluminum, 89W, Athlon / Phenom CPU Cooler, Socket AM2/AM2+/AM3, Aluminum, 95W, nMEDIAPC ICETANK CPU Cooler, Socket 754/940/939/AM2/775/478, Copper/Aluminum, Core i7 Quad Core CPU Cooler, Socket 1366, Aluminum/Copper, 130W, Thermaltake CL-P0497-Thermaltake CPU cooler Intel core 2 Duoe CL-P0497 Aluminum , Core i7 Extreme CPU Cooler, Socket 1366, Aluminum/Copper, 130W, Hyper 101i CPU Cooler, Socket 1155/1156/775, Copper/Aluminum, Evercool EC-CI01-9525EP Aluminum CPU Cooler, for Intel Core i7 Processor 920-965, [105166] Thermaltake CPU Cooler CLP0556 Core i7/i5/i3 LGA1156 95W TDP Aluminum 4, [80919] Thermaltake CPU cooler Intel Core 2 Duo CL-P0497 Aluminum 3pin, Evercool HPH-9525EA Aluminum Base CPU Cooler for Intel LGA775 CPU, PC Computer 3 Pin Heatsink CPU Aluminum Cooler Fan, TITAN, TTC-NK54TZ CPU Cooler, Socket 755, Copper/Aluminum, Retail, Aluminum DC CPUAluminum DC CP Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, Aluminum DC CPU Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, Aluminum DC CPU Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, Aluminum DC CPU Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, PC Computer 3 Pin Heatsink CPU Aluminum Cooler Fan, Aluminum DC CPU Cooling Fan Cooler Heatsink For CPU AMD Socket 89W, PC Computer 3 Pin Heatsink CPU Aluminum Cooler Fan, Titan DC-155A915Z Series Aluminum CPU Cooler, DC-155A915Z/RPW , ThermalTake CLP0556 CPU Cooler for Intel LGA1156 CPUs, Aluminum Extrusion, Athlon / Sempron CPU Cooler, Socket AM2/AM2+/AM3, Aluminum, 45W, Athlon/Phenom CPU Cooler, Socket AM2/AM2+/AM3, Aluminum, 80W,