Production of high thermal conducting aluminum-graphite composite materials by the press-squeeze method utilizing porous graphite preforms and aluminum alloys

Consideration is given to the technological process of producing high thermal conducting aluminum-graphite composite materials by press-squeeze method utilizing porous graphite preforms and aluminum alloys. It is shown that the rate of press-squeeze process, aluminum alloy composition provide dense, defect-free and non-porous thermal interface between graphite and matrix alloy, it is noted the absence of crystal inclusions of third phases, such as SiC, Al4C3. An example of evaluation of thermal conductivity of the sample of composite material is given with consideration of graphite particles orientation and matrix-filler thermal interface heat conductivity.

Experimental Study on the Effect of Interface Heat Transfer on Performance of Thermoelectric Generators

Thermoelectric generators (TEGs) have attracted more and more attention for their usage in waste heat recovery techniques. A key challenge in thermoelectric power conversion is to create a significant temperature difference across the TEG. The interface heat transfer between heat exchanger and TEGs plays a key role in TEGs’ performance when the heat exchanger and TEGs have been determined. In this paper different thermal interface materials (TIMs) were used to create different interface heat transfer conditions. Firstly, the thermal interface conductance of TIMs is measured by using a steady state method. Then the performance of TEGs at different interface heat transfer condition was evaluated. It was found that interface heat transfer between heat exchanger and TEGs has a significant effects on the performance of TEGs.

The effect of liner design and materials selection on prosthesis interface heat dissipation

Background and aim: Thermal discomfort often affects prosthesis wearers and could be addressed by increasing liner thermal conductivity. This note explores a liner made from thermally conductive silicone and two additional alternative liner designs. Technique: Thermally conductive silicone was used to create a conductive liner and a hybrid liner. Additionally, one with open elements was made. These were compared with a plain silicone liner and a no liner scenario. Scaled down liner prototypes were used due to the high-cost of the thermally conductive silicone. Temperature decay profiles were collected by attaching thermistors to a heated liner phantom and used to evaluate scenarios. Discussion: No scenario performed much better than the plain silicone liner. Implementation of passive solutions may be easier, but alternative liner materials are unlikely to affect dissipation enough to address thermal discomfort. Based on this work, future research efforts may be better spent developing active thermal discomfort solutions. Clinical relevance Thermal discomfort can increase the probability of skin damage, reduce prosthesis satisfaction and, ultimately, the quality of life. The prosthesis-wearing experience could be improved if thermal discomfort can be addressed by technological improvements.

Development of thermal conductive sheet with low interfacial heat resistance

In order to reduce total heat resistance, we focused on reducing an interfacial heat resistance between high thermal conductive sheet composed of resin and heat conductive filler and metal such as Cu or Al. The interfacial heat resistance was determined by dispersion of high heat conductive filler and interfacial residual stress. The good dispersed sheet shows lower interfacial resistance than poor dispersed sheet, The interfacial residual stress causes an poor contact to metal to make void in the interface. To consider the effect of those facts, we successfully developed the high thermal conductive sheet with extremely low interfacial resistance. The interface heat resistance is below 0,009W/C.

Modeling of Interface Heat Flux and Thermal Field of Mold Materials during Gravity Die Casting

One of the key controllable and influential factors to obtain a casting simulation, representative of reality, is the choice of boundary condition. The thermal boundary condition to be specified at the metal-mold interface must account for complex heat transfer phenomena associated with solidifying casting. The present study aims at estimating the heat flux at the interface of the mold and the solidifying metal by Inverse Heat Conduction Problem (IHCP) approach. Solidification studies were conducted on casting of aluminum reinforced with boron carbide composite. Copper, cast iron and stainless steel were used as mold materials. The temperature data of the mold was recorded from the beginning to end of solidification using k-type thermocouples connected to temperature data logger. This time-temperature history was used as input to the IHCP algorithm to simulate the interface heat flux and thermal field of the mold. The results indicate that the interface heat flux is highly transient and varies with the variation in the thermo-physical properties of the mold materials. The study also demonstrates that heat conduction is one dimensional in copper mold and two dimensional in cast iron and stainless steel mold during phase change.