The material presented in this video are some highlights from NADCA’s online webinar - High Integrity Die Casting: Alloys for High Integrity Die Casting. In this webinar, all aspects of aluminum high integrity die casting alloys will be covered: from AA numbering, basic metallurgy, the role of alloying each element, impurities and their impact on part quality and properties, all the way to different alloy families and existing alloys currently used or under development, with their advantages and disadvantages, current and potential applications as well as achievable properties (using different heat treatments) with each of them.
Let's start with silicon. Of course that is the most important one in the casting alloys. It promotes fluidity and castability; reduces shrinkage; improves hot tear resistance and feeding characteristics. It increases strength and stiffness and we'll see that later on in a graph. It also reduces specific gravity. That's not as important for us. It also improves pressure tightness and corrosion resistance of castings. that sometimes is important in high integrity die casting. In hyper-eutectic alloys, so that means above the eutectic point of 12.6 percent. Silicon is used to reduce wear resistance. And of course the most famous alloy is 390 or 391 type. As I said, most die casting alloys are around 8-12 percent silicon.
Casting properties of Al-Si alloys in relation to the Al-SI binary equilibrium diagram.
b. feeding behavior
c. shrinkage sensitivity
d. uniformity of shrinkage
e. hot tear tendency
For information on purchasing a downloadable copy of this webinar in its entirety, please visit: http://www.diecasting.org/store/detail.aspx?id=WEB143