|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Cast Shop Technology
||C-41: Evaluation of Stress Relief Processes Used on High Pressure Aluminum Die Casting Dies
||Thomas R Watkins, Philip J. Maziasz, Ercan Cakmak, Jeffrey B. Cornett, James Saylor
|On-Site Speaker (Planned)
||Thomas R Watkins
High pressure die casting is the process of using high pressure to inject molten aluminum into cooled steel molds called dies. The process is able to produce castings with complex geometries at quantities of about 1,000 per day on a single machine. Aluminum is injected at temperatures about 650 ̊C and then cooled to a solid in a matter of seconds. Repeating this process thermally cycles the steel dies. The constant expansion and contraction of the die surfaces from thermal cycling induces tensile residual stresses in the surface which, over a long enough time, can cause cracking in the die. These cracks can lead to die failure due to breakouts (when part of the die breaks off) or coolant leaks when cracks propagate to cooling passages that exist internally in the die core.
Stress relieving is done as part of regular maintenance to relieve the residual stress from use, machining, or welding to prevent cracking in dies. A greater understanding of the difference between traditional thermal stress relief to that of vibratory stress relief is needed. Stress measurements using both X-ray and neutron diffraction methods coupled with advanced microscopy will be discussed.
||Planned: Light Metals