Pin Fin Array Heat Sinks By Cold Spray Additive Manufacturing: Economics Of Powder Recycling

As a result of the rise in processing power demands of today’s personal computers, water cooled pin fin heat sinks are increasingly being employed for the cooling of graphical processing units (GPUs). Currently, these high performance devices are manufactured through high-cost, high-waste processes. In recent years, a new solution has emerged using the Cold Gas Dynamic Spray (CGDS) process, in which pin fins are directly manufactured onto a base plate by spraying metallic particles through a mask. This process allows for a high degree of adaptability to different GPU shapes and sizes not achievable in any other process to date. One drawback of this new additive manufacturing process is low deposition efficiency, resulting in a fair portion of the feedstock powder being wasted as substrate sensitivity to heat and mechanical residual stresses requires the use of low spray parameters. This work aims to demonstrate the feasibility of using powder recycling to mitigate this issue and compares heat sinks sprayed with recycled powder to their counterparts sprayed with as-received powder. In so doing, CGDS is shown to be a highly flexible and economically competitive process for the production of pin fin heat sinks.