APPLICATION OF LASER ADDITIVE MANUFACTURING TO PRODUCE DIES FOR ALUMINIUM HIGH PRESSURE DIE-CASTING#

ENGLISH ABSTRACT: A number of laser additive manufacturing (LAM) technologies can produce fully-dense metal components that potentially offer opportunities to apply the technology in die or mould making (known as rapid tooling). From these LAM technologies, three were selected for evaluation of their suitability as die cavity inserts in the manufacture of high pressure die-casting (HPDC) dies. Apart from comparing the different LAM inserts with one another, their performance was also compared with components manufactured in a standard hot work steel. In the HPDC process, the die is unique to each component to be produced. Die cavities in particular are subjected to demanding conditions, such as cyclic heating caused by the introduction of molten aluminium at over 650°C, followed by cooling in water-based die release medium at temperatures around 25°C. Besides cyclic heating, the die cavities are also exposed to pressures exceeding 1500 MPa during the injection of molten aluminium into the cavities. This application of LAM, therefore, poses extreme challenges to the technology. The results of this study confirmed that the metals used in some of the LAM technologies did indeed meet the demanding requirements of the current application, and can lead to significant time- and cost-saving during product or process developments. Based on these findings, a number of recommendations are made for users interested in the application of LAM to produce die cavities. AFRIKAANSE OPSOMMING: ’n Aantal laser laagvervaardigingstegnologie (LLV tegnolgie ) is in staat om volledig digte metaalkomponente te lewer, wat tot gevolg het dat hierdie tegnologie potensieel vir vormingsmatrys- of gietmatrysvervaardiging gebruik kan word (bekend as snelgereedskap). Drie van hierdie LLV tegnologie is gekies vir evaluasie van hulle geskiktheid as gietvorminsetsels tydens die vervaardiging van gietmatryse vir ho druk matrysgiet (HDMG). Benewens die onderlinge vergelyking van die verskillende LLV insetsels met mekaar, is hulle werkverrigting ook vergelyk met komponente wat in standaard warmwerkstaal vervaardig is. In die HDMG proses is die gietmatrys uniek aan elke komponent wat gevorm word. Die matrysholtes word veral aan uiterste toestande onderwerp, soos sikliese temperatuur-verskille, veroorsaak deur die blootstelling aan gesmolte aluminium by meer as 650°C, direk gevolg deur afkoeling in watergebaseerde smeermiddel by temperature van tipies 25°C. Buiten sikliese verhitting, word die matrysholtes ook tydens die inspuit van gesmolte aluminium in die holtes blootgestel aan drukke ho