Thursday, October 22
Protecting the Die Surface
9:00 am – 10:30 am CDT
Session Chair: Peter Ried
Water-Free Electrostatic Spray for High Pressure Die Casting
Koji Togawa (Aoki Science); Brian Springer (Ultraseal International)
Water- based die lubricants (WBD) are widely used in the world. A new generation of Water Free Releasing (WFR) agent containing no water overcame the disadvantages of WBD in 2004. Because of very small amount of spray (1/800 over WBD), LUBROLENE WFR provided technical, economical & environmental benefits.
In 2009, developments of “Electrostatic Charged spray gun” for die-casting use and “an innovative WFR agent for Electrostatic spray” so called LUBROLENE WFR-EC was introduced which further improved performance for deep ribs and complex castings. With this innovative WFR-EC which has unique features for productivity, economics, and environment.
Analysis of Five Different AlCrN PVD Coatings Deposited onto H13 Steel for Lube-Free Aluminum Die Casting Applications
Nelson Delfino de Campos Neto, Andras Korenyi-Both, Stephen Midson, Michael Kaufman (Colorado School of Mines)
AlCrN PVD coatings are excellent candidates for die coatings to reduce or eliminate the use of conventional lubricants in aluminum die casting. Different AlCrN coatings are commercially available, and an understanding of their different characteristics is needed to ensure their optimum performance in the die casting process. In this work, a range of characterization techniques and tests have been applied to differentiate and understand five separate AlCrN coatings provided by two suppliers. Testing performed of the coatings included composition, microstructures, mechanical properties, wear resistances, and adhesion resistances to molten aluminum alloys. Significant differences were observed in the characteristics and performance of the five coatings, which are documented in this paper.
PVD Coating for Zinc Die Casting Die
Jay Anderson (Anderson Die Casting)
The intention of this project is to build on the research and plant trials done previously on dies used in the aluminum process and see how a similar PVD coating would help improve the tooling performance in the zinc die casting process. An existing die which has had a history of accumulating solder on the core inserts was chosen to be used in the project. The die runs in a Techmire 44NTX machine. Two sets of core inserts were used for the evaluation. The original set of core inserts are an uncoated H-13 while the second set of cores were built to be identical but in addition have the Phygen’s FortiPhySM PVD-Based, Chromium Nitride (CrN) Tool Coating.
The project will evaluate the effect of the PVD coating on the process and attempt to quantify the reduction in solder on the cores, change in cycle time, and potential reduction in part porosity.
Understanding and Monitoring the Die Casting Process
10:45 am – 12:15 pm CDT
Session Chair: Yeou-Li Chu
The Need for a New Approach to Solder in Die Casting
Alex Monroe (Mercury Marine); Paul Sanders (Michigan Tech University)
Solder remains one of the most common defects in high pressure die casting (HPDC). It is most simply defined as aluminum stuck to the die surface. The common technology to control it is die lubricant, but this leads to die damage via thermal shock. Due to this wear, solder can be considered the primary cause of die failure. For nearly 50 years, a thermodynamics and kinetics understanding of solder has been accepted while explicitly assuming that other mechanisms are not important. Upon review of this work, it will be shown that thermodynamics and kinetics cannot adequately explain three common industrial observations. First, solder forms much faster than calculated based on diffusion couple experiments. Second, the alloys that are industrially observed to solder less form intermetallic phases quicker and dissolve the steel faster than alloys that solder more rapidly. Finally, the reaction layer is not strong enough to enable the buildup commonly observed on soldered dies. For these reasons, it is proposed that a new mechanism is required to understand and eliminate solder.
Remote Monitoring of Shot Sleeve Temperature for Process Control
William Sames, Dale Lawhorn, B. Stok, J. Duhovnik, B. Taljat (HTS International)
HTS has developed a cloud-connected, thermal remote monitoring system for shot sleeves and die components. This system utilizes thermocouples to collect data directly from steel, to monitor the physical condition of process results (vs process inputs on the machine) to allow die casters a new approach to stay within a desirable operating window. Theoretical simulations and correlated experiments are presented as background to justify the validity of this approach. This system was deployed in Fall of 2019 on a shot sleeve and used to monitor the casting process throughout many dies changes and different types of shot tips and spray conditions. Shot sleeve temperatures were shown to vary periodically with cycle. Furnace temperature data was retrieved and analyzed with respect to shot sleeve temperature, in order to analyze high temperature transient events in shot sleeve temperature –however, no correlations were found. iTherm® shot tips with steel rings led to sleeve operational temperatures averaging 370°C-400 °C, however unexplained high and low daily average temperatures were observed for both styles of shot tips evaluated. The impact of downtime was shown to cause significant temperature drops in the sleeve tested, due to absence of thermoregulation lines. Alerts were set up within the system to provide bounds of acceptable operating temperatures, which can be used for additional machine alarms.
Three Plate Die Biscuit Detection Monitoring
Michael Gran, Robert Michael Marconi (RCM Industries – Aallied Die Casting Company)
3-plate dies present a unique challenge in biscuit removal and detection. The runner and biscuit system must fall between the cover A and B plates and clear the space between them. Detecting a complete runner system is critical to avoiding an unsafe condition or damage to the tool. Typically, sensors (e.g. paddle switch, laser, light curtain) are used to detect the runner as it evacuates the die space. However, there are problems inherent to this method. These detection methods are limited to detecting that something fell through but not that everything fell through. Failure to identify that everything has passed through results in a biscuit stuck in the shot sleeve or in the A plate, causing additional attention from the operator. This project aims to identify and test viable detection methods for ensuring complete removal of the gating system on 3-plate dies. Various sensing/detection technologies will be identified as viable candidates for in-plant testing. In a preliminary search, a fiber optic laser sensor was chosen as the most economical option.