Overview of the 2016 R&D Strategic Plan and Roadmap
The NADCA Research & Development Strategic Plan and Roadmap, which guides the direction of the NADCA R&D Program, has now been established for 2016. The Strategic Plan and Roadmap is updated on an annual basis and the overview is published in the July issue of this magazine. . Input is provided by members of the NADCA Technical Committees and the industry to ensure that the Plan continues to address the current needs of the industry. The industry needs define the strategic areas requiring technological advancement and appropriate research projects that respond to the needs. However, because the available funding for research projects is typically not sufficient to support all of the defined research projects, prioritization of the projects is a necessity. As a result, the 2016 R&D Strategic Plan and Roadmap consists of 13 projects with a total leveraged value of these projects (funding plus cost share) of $3.3 million. A well balance portfolio of projects has been maintained this year, good progress continues, and beneficial results continue to be provided, even though all of the defined research projects would equate to a leveraged value in excess of $40 million.
This article presents a synopsis of the 2016 NADCA R&D Strategic Plan and Roadmap, features highlights from two projects, and presents a brief objective for all 13 projects, and lists future project ideas.
The strategic plan displays areas that have been identified by industry as strategic and ensures that efforts are applied toward further development and advancement of the strategic areas. Several strategic areas have been identified and are targeted for technological advancement. The primary strategic areas are Products and Markets, Materials Technology, Manufacturing Technology, Environmental Technology, and Industry Health & Profitability. Each of these primary areas contains sub-categories such as cast materials development, computer modeling, die materials and die surface engineering, process technologies, and others. The roadmap defines the specific R&D activity or research projects that are applied toward the advancement each strategic area. Technological advancement of the strategic areas is targeted to provide many benefits such as, higher performance alloys, die life extension, quality enhancement, productivity improvement, scrap reduction, cost reduction and lead-time reduction.
The NADCA roadmap is currently populated with 13 research projects. (See Table 1). A brief statement of objectives for each project is provided under Current Projects. The total leveraged value of the portfolio of current projects, as mentioned above, is approximately $3,300,000. Sources of funds include the United States Department of Defense (DOD) Defense Logistics Agency R&D (DLA/R&D) Casting Solutions for Readiness (CSR) Program, and the American Metalcasting Consortium (AMC); the National Institute for Standards and Technology (NIST; and NADCA.
#193 Evaluation of Pulsed Spray
NADCA initiated work on this current project because it has been suggested that pulsing of die lubricant may be more effective than continuous spray. The opportunities include more efficient cooling, reduced spray usage, extended die life, and shorter spray cycles. Opportunities such as these can provide high dividends to the die casting industry. To evaluate pulsed spray and measure the actual level of benefits, NADCA sought and has partnered with a die caster interested in implementing pulsed spray.
A specific die cast component for which pulse spray will be demonstrated has been selected, however the question was whether the current reciprocator could be programmed to pulse. With assistance from the reciprocator manufacturer, it was determined that the equipment could pulse down to 0.5 seconds. Cycling the spray equipment at 0.5 second was found to not be reliable, but programming to 0.7 seconds to 0.8 seconds actuated the spray heads reliably. The standard spray cycle being used in production for the selected die casting is a continuous spray of 2.5 second.
The next step was to conduct die life, die stress level, and die temperature computer simulations. The simulations indicated that a spray routine of 0.8 seconds on, 0.8 seconds off, and 0.8 seconds on, for a total spray cycle time of 2.4 seconds, would improve die life to some extent, reduce peak stress levels on the die cavity surface, and increase the die temperature in the hot spot by about 9oC. The lubricant reduction was calculated to be 36%. Having only a slight temperature increase indicates that sticking of the casting to the die should not be an issue. Although the reciprocator being used could not reliable pulse down to 0.5 seconds, a 0.5 second routine (0.5 seconds on, 0.5 seconds off, etc.) for a total of 2.5 seconds was also modeled. The results indicated that die life increase would be negligible, stress was slightly lowered, and the die temperature profile was essentially the same as the 2.5 second continuous spray. Lubricant reduction would be 40%.
The next step is to validate the simulation results in production. The production trial is anticipated to commence by the end of summer.
Although it has been shown that older existing equipment may have the capability of pulsing, more ideally is pulsing at higher frequencies. For example, the E-Nozzle with pulsed width modulation developed by Rimrock can pulse up to 250 cycles per second. Preliminary results from this technology is showing even greater benefit with die lubricant reduction up to 82%.
#190 Qualification of Additive Manufacturing Processes and Procedures for Repurposing and Rejuvenation of Tooling
The additive manufacturing project entitled “Qualification of Additive Manufacturing Processes and Procedures for Repurposing and Rejuvenation of Tooling” was recently completed. Meeting the objective of developing, evaluating and qualifying novel methods for the repair and reuse of die casting dies, a number of processes have been qualified and a qualification procedure has been established. Qualification includes impact testing, bond strength testing, tensile testing, microstructural analysis and radiographic examination. The additive manufacturing processes that were qualified include: laser wire deposition, hot wire laser deposition, direct metal deposition, electron beam wire, laser engineered net shaping, and 3D printing. The processes were provided by the following sources: Alabama Laser, Lincoln Electric, DM3D, Sciaky, Whitfield Welding, Keystone, Benet Laboratory, and Joining Technology. It was found through qualification testing that Maraging Steel Grade 250 was preferred over H13 due to its lower as-deposited hardness (low-to-mid 40’s HRC as opposed to the H13 as deposited hardness in excess of 50 HRC) and no need for subsequent tempering.
After laboratory evaluation and qualification of the aforementioned processes for the Maraging steel, die components for aluminum die casting were repaired with the various process and placed back in service. All components are performing well and one has achieved over 73,000 shots thus far.
A follow-on project has been proposed for evaluating cores with conformal cooling lines.
Over the past year, three projects have been completed and three new projects have been initiated. The three completed projects are: #186 Effect of Slow Cooling Rate on Impact Strength of Superior Die Steels; #190 Qualification of Additive Manufacturing Processes and Procedures for Repurposing and Rejuvenation of Tooling; and, #191 T5 Heat Treating of Conventional Die Castings Phase III. The three new projects are: #195 Zinc Creep Sensitivity to Section Thickness; #196 T6 Heat Treatment of Aluminum Die Castings; and #197 Roadmapping for the Metalcasting Industry A statement of objectives for each of the current projects is as follows.
Project 181: Thin Wall Aluminum and Magnesium (S. Udvardy, NADCA; D. Schwam, CWRU; and R.A. Miller, OSU)
Research Objectives: To develop aluminum and magnesium based alloys that possess substantially higher fluidity than A380 aluminum and AZ91 magnesium and that are easy to produce and recycle. In addition, die design and processing strategies will be defined for the production of extreme thin wall castings.
Project 182: SSM and Squeeze Casting of 201 and 206 Type Alloys (S. Udvardy, NADCA; D. Schwam, CWRU; and R.A. Miller, OSU)
Research Objectives: To develop SSM parameters for robust processing of high strength alloys such as 206 and 201 and to assess the feasibility of squeeze casting such alloys. The impact of specific alloy chemical constituency on hot tearing tendencies and the effect of processing variables, such as die temperature, gate velocity and pressure will be assessed.
Project 183: Standards and Transition (S. Udvardy and J. Brennan, NADCA)
Research Objectives: To identify company specific aluminum casting alloys that offer performance advantages over casting alloys for which industry-wide standards currently exist, confirm the property advantages and add the chemistry and properties to the NADCA Product Specification Standards. Pursue registration of the alloys with the Aluminum Association.
Project 195: Zinc Creep Sensitivity to Section Thickness (Frank Goodwin, ILZRO)
Research Objectives: To test different section thicknesses (0.8, 1.5 and 3.0mm together with 0.4mm if available) for Alloy 5 at 60, 90 and 120C, to determine the effect of section thickness on creep properties and to determine whether the “C’ creep equation” can be generalized for this range of section thickness, expanding the properties database for this alloy.
Project 196: T6 Heat Treating of Aluminum Die Castings (Stephen P. Midson, The Midson Group)
Research Objectives: To characterize the impact of full T6 heat treating parameters on the mechanical properties of conventional die castings produced from both strontium modified, low-iron 360-type alloys and low-iron 380-type alloys. Salt baths are to be evaluated for solutionizing and various time-temperature exposures will be evaluated to select the optimum aging treatment.
Die Materials & Die Surface Engineering
Project 176: Evaluation of Candidate Commercial Coatings (Qingyou Han, Purdue University)
Research Objectives: To evaluate the soldering performance of die materials and select commercial coatings with the fast high frequency ultrasonic vibration test method. Various aluminum alloys, those known to be prone to solder and those known not to be prone to solder will be utilized for the evaluations.
Project 188: Cavitation Measurement using an ABS Acoustic Bubble Spectrometer (Qingyou Han, Purdue University)
Research Objectives: To evaluate the feasibility of using ABS acoustic bubble spectrometer for the detection of cavitation in fluid and using 3DynaFS, a CFD software, for the prediction of multiphase flows with cavitation and bubbles. Cavitation testing and modeling is to be performed.
Computer Modeling and Design Aids
Project #132: Modeling Heat Removal by Die Spray Consortium (R. Allen Miller, The Ohio State University)
Research Objectives: To develop an approximate model of heat removal by spray based on first principles and consistent with the known empirical data. The model is intended to provide information on the effectiveness and limitations of die spray so spray usage can be reduced. Specific issues to be addressed are: 1) heat flux as a function of spray parameters; 2) spray parameters as a function of operational parameters; 3) heat transfer coefficient; and, 4) spray program optimization parameters.
Project #175: Achieving Flash-Free Die Casting (Jerry Brevick, The Ohio State University)
Research Objectives: To evaluate the concept, assumptions, and practical effectiveness of employing engineered die cavity overflows to dissipate the energy of the rapidly decelerating dynamic shot system mass in a controlled manner, so as to eliminate die flashing. Included will be the design and manufacture (or modification) of an experimental die set with in-cavity pressure sensors, and easily reconfigurable overflows on the periphery of the die cavity.
Project #179: Lube Free Die Casting (Michael Kaufman, Colorado School of Mines and R. Allen Miller, The Ohio State University)
Research Objectives: To develop permanent or semi-permanent die coatings that are non-wetting/non-sticking with respect to molten aluminum, magnesium and zinc, and self-lubricating in order to reduce cycle time and process cost, as well as improve quality. To develop appropriate modeling methods for the process and die design taking into consideration that elimination of die spray will eliminate the die cooling aspect of the spray.
Project #192: Methods for Evaluation of Die Lubricants Used in Al Die Casting (D. Schwam, CWRU)
Research Objectives: To identify the key properties for measuring the performance of die lubricants and determine the testing methods for quality assurance of the incoming product.
Project #193: Evaluation of Pulsed Spray (S. Udvardy, NADCA; John Pierson, Rimrock; Alex Monroe, Mercury Marine)Research Objectives: To model and demonstrate the pulsed spray technique for reduced spray time and reduced spray amount. Determine potential cost savings.
Project 197: Roadmapping for the Metalcasting Industry (AFS, NADCA, SFSA, NFFS, and SCRA)
Objectives: To establish a new roadmap for the metalcasting industry identifying the current and future needs of the metalcasting industry. The last metalcasting roadmap was established in 2002 and is out-dated.
Ideas for Future Projects
Over the past two years several ideas for new projects that can further advance the state of die casting technology have been generated. A sampling of these projects which may be initiated through funding that is secured in the future is shown in the list below,
- High Temperature Al Alloys
- Structural Magnesium
- Impact of Defects on Performance of Castings or Replacement for ASTM E505
Die Materials & Die Surface Engineering
- Disposable Cores
- Die Materials for Casting of High Temperature Alloys
- Local Melting for Die Improvement (Laser Glazing, Friction Stir)
- Ejection Force Prediction
- Modeling for Properties Throughout a Cast Geometry
- Modeling for Structural Castings
- Hot Chamber Aluminum
- Die Casting of Steel, Titanium and Nickel
- Porosity Free Castings – cooling rate impact and soundness prediction – configuration mapping
The 2016 NADCA R&D Strategic Plan and Roadmap has been established. The portfolio of projects remains as well balanced as possible with the current level of funding support. Numerous benefits have been provided to the industry through the R&D Program including new alloys with higher properties, new die steels for longer life and faster heat extraction, cost reduction, productivity improvement, quality enhancements and others. These benefits provide opportunities for improved profit and the ability to better compete in the domestic and global marketplace. New project ideas to support the needs of the industry and additional sources of funds to initiate new projects continue to be sought.
Participate in the NADCA R&D Program
The Technical Committees meet three times per year and the meetings are open to members. Participants not only learn about new developments and how to utilize the developments, but also assist in suggesting new projects, selecting projects, and steering the direction of current projects. Opportunities for conducting plant trials and transferring technology to your shop floor also exist. Contact the NADCA Research Department for more information.
Table 1. Current R&D Projects Categorized by General Topic Area