Complex Structure Modification and Improvement of Properties of Aluminium Casting Alloys with Various Silicon Content

The possibility of using complex structure modification for aluminium casting alloys’ mechanical properties improvement was studied. The fluxes widely used in the industry are mainly intended for the modification of a single structural component of Al–Si alloys, which does not allow unifying of the modification process in a production environment. Thus, a new modifying flux that has a complex effect on the structure of Al–Si alloys has been developed. It consists of the following components: TiO2, containing a primary α-Al grain size modifier; BaF2 containing a eutectic silicon modifier; KF used to transform titanium and barium into the melt. The effect of the complex titanium dioxide-based modifier on the macro-, microstructure and the mechanical properties of industrial aluminium–silicon casting alloys containing 5%, 6%, 9%, 11% and 17% Si by weight was studied. It was found that the tensile strength (σB) of Al–Si alloys exceeds the similar characteristics for the alloys modified using the standard sodium-containing flux to 32%, and the relative elongation (δ) increases to 54%. The alloys’ mechanical properties improvement was shown to be the result of the flux component’s complex effect on the macro- and microstructure. The effect includes the simultaneous reduction in secondary dendritic arm spacing due to titanium, the refinement and decreasing size of silicon particles in the eutectic with barium and potassium, and the modifying of the primary silicon. The reliability of the studies was confirmed using up-to-date test systems, a significant amount of experimental data and the repeatability of the results for a large number of samples in the identical initial state.

Taxonomy, Saving Potentials and Key Performance Indicators for Energy End-Use and Greenhouse Gas Emissions in the Aluminium Industry and Aluminium Casting Foundries

Increasing energy efficiency within the industrial sector is one of the main approaches in order to reduce global greenhouse gas emissions. The production and processing of aluminium is energy and greenhouse gas intensive. To make well-founded decisions regarding energy efficiency and greenhouse gas mitigating investments, it is necessary to have relevant key performance indicators and information about energy end-use. This paper develops a taxonomy and key performance indicators for energy end-use and greenhouse gas emissions in the aluminium industry and aluminium casting foundries. This taxonomy is applied to the Swedish aluminium industry and two foundries. Potentials for energy saving and greenhouse gas mitigation are estimated regarding static facility operation. Electrolysis in primary production is by far the largest energy using and greenhouse gas emitting process within the Swedish aluminium industry. Notably, almost half of the total greenhouse gas emissions from electrolysis comes from process-related emissions, while the other half comes from the use of electricity. In total, about 236 GWh/year (or 9.2% of the total energy use) and 5588–202,475 tonnes CO2eq/year can be saved in the Swedish aluminium industry and two aluminium casting foundries. The most important key performance indicators identified for energy end-use and greenhouse gas emissions are MWh/tonne product and tonne CO2-eq/tonne product. The most beneficial option would be to allocate energy use and greenhouse gas emissions to both the process or machine level and the product level, as this would give a more detailed picture of the company’s energy use and greenhouse gas emissions.

Sistem Pendingin Menggunakan Thermalelectric Cooler Guna Menstabilkan Temperatur Box Panel Kontrol Mesin Die Casting

<em>PT. Chemco Harapan Nusantara plan 1 Cikarang merupakan perusahaan yang bergerak di bidang manufaktur automotive brake system dan aluminium casting parts. Pada proses pembuatan casting part diperlukan sistem pendinginan, salah satunya pada lemari box panel kontrol mesin die casting 650T yang berisi komponen elektrik. Latar belakang permasalahan yang ditemukan terjadi pada sistem pendingin AC Konvensional yang digunakan. Kondisi temperatur ruang panel kontrol mesin yang tinggi. Penyebab permasalahan yakni kompresor yang mengalami overheat karena temperatur lingkungan factory II (casting) yang tinggi. Dampaknya mengakibatkan berkurangnya lifetime hingga berujung rusaknya komponen elektrik tersebut. Solusinya adalah dengan pemanfaatan sistem pendingin thermalelectric yang digerakkan oleh arus DC yang masuk ke modul. Tujuan penelitian ini adalah pemanfaatan alternatif sistem pendinginan dan menguji performa sistem pendingin Thermalelectric. Komponen utama pendingin ini meliputi kerangka pendingin, Adaptor, Modul Thermalelectric, thermostat, heatsink dan fan. Metode ini meliputi identifikasi masalah, studi pustaka, menguji performa pada satu buah modul thermalelectric, pengumpulan data pengujian, dan pengolahan data. Parameter pengujian yaitu waktu pada saat pengoperasian dengan mengamati beda temperature yang dihasilkan oleh satu buah modul thermalelectric pada kedua sisi modul guna menggetahui berapa arus yang masuk, panas yang diserap maupun panas yang dipindahkan pada saat pengoperasian pendingin thermalelectric. Hasil dari pengaplikasian pendingin panel dengan data pengujian yang telah diolah pada perhitungan performa untuk satu buah modul thermalelectric dalam penyerap panas yang telah dirata-rata adalah sebesar 44.89 Watt dengan beban pendinginan yang telah dikaji sebesar 1061.06 Watt. Serta arus dan tegangan pada saat pengoperasian sebesar 4.48 A dan 9.29 V. </em>