【正文】 Isostatic Pressing on CastAluminum, Journal Of Metals, November 1997, pp. 3839. [5] . Hebeisen, . Cox, J. Turonek, R. Stack, The Effect of Densal Processing on the Properties of a Cast Aluminum Steering Knuckle, SAE Technical Publication,2020. [6] . Mashl, . Hebeisen, D. Apelian, . Wang, Hot Isostatic Pressing of A356 and 380/383 Aluminum Alloys: An Evaluation of Porosity, Fatigue Properties and Processing Costs, SAE Technical Publication 2020010062. [7] . Diem, S. Mashl, R. Sisson, Cost Effective Densification of Critical Application Aluminum through Simultaneous Densal and Solution Heat Treatment. Part 1 Testing Industrial Castings, TBA. [8] . Brooks, ASM Handbook, vol. 4, ASM International, Materials Park, OH, 1991,pp. 823879. [9] S, Shivkumar, C. Keller, D. Apelian, Aging Behavior in Cast AlSiMg Alloys,American Foundrymen’s Society Transactions, Vol. 90, No. 179, pp. 905911. [10] D. Apelian, S. Shivkumar, S. Sigworth, Fundamental Aspects of Heat Treatment of Cast AlSiMg Alloys, American Foundrymen’s Society Transactions, vol. 89, No. 137, pp. 727742. [11] C, Bergmann, HIP Quenching in 2020 Bar Argon Gas, Metal Powder Report, October 1990, pp. 669671. [12] . Wall, Chemical Thermodynamics,W. H. Freeman and Company, San Francisco , CA, 1958. 。 C, while natural aging occurs at room temperature. The homogenization attained in the previous steps insures a uniform dispersion of the particulates grown in the aging step. Artificial aging to reach maximum strength deems the temper of the casting as T6, where natural aging gives the casting the temper designation T4. Hot isostatic pressing, or HIP, is typically performed before heat treatment and is a means of eliminating the porosity in castings. HIP surrounds the casting with a pressurized gas, which applies a hydrostatic force to the surface of the casting while at elevated temperature to facilitate material flow. The dominant densification mechanism in the casting during the initial stages of the HIP process is plastic flow. As castings spend additional time at maximum temperature and pressure the dominant densification mechanisms change, first to powerlaw creep, then to diffusional creep mechanisms (NabarroHerring, and Coble creep). The overall effect is the welding of isolated porosity within the casting [Atkinson]. Due to the time intensive nature of the HIP process, several variants of the original process have been developed to maximize the returns of the HIP process while minimizing process time and cost for the production of critical aluminum castings. Liquid hot isostatic pressing (LHIP) uses a heated inpressible liquid as the pressurizing media [Chandley]. The guiding principle behind this manufacturing process states that the majority of the time spent in the traditional gas HIP process is spent pressurizing and depressurizing the pressible gas media. In the LHIP process, the castings are immersed in the liquid salt bath and the entire salt bath container is pressurized via a hydraulic ram very quickly. By this method, maximum pressure can be reached in seconds rather then the several hours required in the HIP process. Furthermore, this process could be integrated into a continuous casting process [Chandley]. However, time spent at peak pressure for an A356 casting in the LHIP process is only about thirty seconds [Romano et al.], which does not allow any of the previously mentioned timedependant creep mechanisms to occur. Bodycote PLC has taken another approach to reducing the cost of the HIP process for aluminum castings. The Densal process is a proprietary HIP process that has tailored the HIP process specifications and hardware specifically for aluminum castings. Time spent at temperature and pressure allows diffusional creep mechanisms to take place. It has been estimated that the Densal process reduces the cost of HIP for aluminum castings by as much as seventy percent [Mashl et al.]. However, further gains in Densal process economy may be possible. Due to the similarity of the process temperatures of solution