Session 3 A – Aerospace
Thursday 12 June 08:30
Development of powder metallurgy titanium impellers
Daniel Cornu, SNECMA, Vernon, France
Daniel Cornu is Snecma Space Engine Division Material and processes expert. He has been working for more than 20 years in developing applications in the field of powder metallurgy like plasmaforming, HIP and additive manufacturing.
SNECMA has started the development of a new rocket engine for upper stage applications; its name is VINCI. The liquid hydrogen turbopump is two-stage centrifugal including one shrouded impeller per stage and the max peripheral speed is 600 m/s. The cost is the
main criterion for the turbopump design. Isoprec®, a new net shape powder metallurgy process developed in a team including Snecma
has been chosen for these components production. For turbopump impeller application the expected benefits of this process are:
– machining simplifications by obtaining Net-Shape surfaces (vanes),
– high dimensional reproducibility,
– good as-HIP material properties.
Thursday 12 June 09:00
A selective net-shape powder metal process for high-performance rocket engine components
Stephen James, Aerojet Rocketdyne, Canoga Park, United States
With over 30 years of non-destructive evaluation methods and techniques, Steve James has worked in developing powder metallurgy parts and ultrasonic reference specimens and standards for 10 years in Aerojet Rocketdyne Company.
Liquid rocket engine performance has historically been constrained by the limitations of materials and processes used for high value component fabrication. Traditional manufacturing processes, such as five axes machining from complex forgings and welding of multiple details, are expensive because of the difficulty to fabricate the materials needed, the complexity of the designs and the low production quantities typically associated with liquid rocket engines. In recent years, there has been considerable focus on reducing production costs, while at the same time increasing engine performance efficiency. Recognizing these cost drivers and design limitations, Aerojet Rocketdyne has been exploring various powder-metal-based processes as potential approaches to lowering costs as well as enabling unique design approaches. Direct-Hot Isotropic Pressure powder consolidation is one of the processes that provides opportunities for many cost, performance and life benefits over traditional manufacturing processes. This method employs sacrificial metallic tooling which functions much like a casting mold to create the expensive machine geometries and is then removed from the part by selective acid dissolution after HIP consolidation of the powder. The benefits of this process include: a uniform microstructure and isotropic properties irrespective of part size and shape; elimination of welds and their associated quality and life limitations; removal of traditional producibility constraints on design freedom; scale-up to large, monolithic parts limited only by the size of existing HIP furnaces; and significantly lower production costs over traditional manufacturing processes. A review of the process showing demonstration components (static and rotating) with application to liquid rocket engines will be described in this presentation.
Thursday 12 June 09:30
HIP process modelling for net shape parts of rocket engine turbopump
Rei Mihara, IHI Corporation, Tokyo, Japan
Rei Mihara is a mechanical engineer in charge of Powder Metallurgy activities for 9 years in IHI Corporation. Also has a professional experience in the field of Material and Structural Design for the Rocket Engine Turbopump.
Abstract The Net Shape HIP process is a suitable approach for both high performance and cost reduction compared to the casting and the machining of forging material, especially for rocket engine turbopump parts. This is because these parts need excellent material properties and high reliability in spite of relatively low production volume. IHI has developed the HIP process modelling tool to predict a dimension of parts after the metal powder compaction at HIP process based on the FEM analysis, which is expected to utilize for manufacturing of rocket engine turbopump parts. The effectiveness of this tool was confirmed by applying to a turbine nozzle with complex shaped blades and by evaluating the difference of dimension between prediction and manufacturing. Furthermore, material data of Ni-base superalloy, which is mainly used for turbopump parts, was acquired to validate the HIP process in terms of the material property. The result shows excellent characteristics in regard to the casting and forging material.
Thursday 12 June 10:00
Problems and development prospects of disks aircraft materials produced via the powder metallurgy technique and direct HIPing
Genrikh Garibov, JSC ”VILS”, Moscow, Russian Federation
Dr Genrikh Garibov is a member of International, Russian and Armenian Engineering Academy. From 1996 – member of American Powder Metallurgy Institute (APMI). From 2000 – member of ASM International. In 2001 he became a member of International HIP Committee IHC. He is a head of Research complex of VILS (All-Russia Institute of Light alloys).
Main problems have been successfully solved and are being solved in the field of the powder metallurgy of disk Ni-base superalloys and related to elimination of powder particle boundaries and a cast structures, as well as a reduction in number and size of non-metallic inclusions in powder bulk are discussed. It is shown that development of a recrystallized structure without powder particle boundaries during HIPing is an essential precondition for production of a monolithic structurally and chemically homogeneous fine-grained material which does not require subsequent plastic working. It has been found that development of such structure depends on a HIP temperature, powder size and a temperature of complete dissolution of ã’ phase (Tã’) of the superalloys to be used. An approach to specification of HIP conditions depending on a temperature of complete dissolution of ã’ phase, size of powder to be used and desired mechanical properties is presented. Examples are shown. The most promising trends in development of Russian P/M disk Ni-base superalloys are outlined and substantiated: a further complication and improvement of alloying, a reduction in size of powder to be used and production of disks with functionally gradientproperties.