EMA CAPABILITIES
EMA is qualified to manufacture superalloy components for the aerospace and gas turbine industries using equiaxed, directionally solidified, and single-crystal technologies. EMA employs investment casting production methods with the goal of producing metal parts that contain:
a small dimensional tolerance
a smooth surface finish, subject to strict metallurgical constraints.
EMA guarantees flexible production for large-scale series. EMA is constantly working to reduce lead times and the time required per product, and to increase efficiency and productivity.
QUALITY
In every department, every single component to be produced is always subject to the EMA Implementation Operational Program. This program is led by the engineering team in collaboration with operators to
analyze in depth all aspects of production related to the launch of the part,
set the injection parameters to produce the specific tooling required for the specific needs,
address the possible causes of production disruptions,
achieve, implement, and maintain best practices in the shortest amount of time
Our goal is to ensure that our customers receive high-quality products at all times. EMA department staff are fully trained, and ongoing professional development is a fundamental EMA policy designed to maintain high-quality standards throughout the entire production cycle.
Ceramic Art Area
Turbine components that feature internal cavities for cooling or weight reduction require a ceramic core inside the component’s wax model. After the casting process, this core is removed through a chemical etching process.
The wax models of these special turbine components (with cores) are injected in a single step in the Wax Area into molds that also accommodate the cores.
The ceramic cores used at EMA for components with equiaxed (EQX), directional (DS), and single-crystal (SX) grain structures range in size from a few centimeters to 70 cm, with diverse and extremely complex geometries.
The operations performed on the ceramic cores within this production area include finishing, impregnation with a material designed to increase mechanical strength during the wax injection phase, dimensional inspection using CMM and GOM (industrial 3D scanner), preparation for wax injection (e.g., insertion of spacers, partial filling with wax, optimization of core-wax adhesion), and visual inspections to verify integrity and compliance with established quality specifications.
Cere Area
EMA manufactures a wide range of components and, consequently, wax models weighing from a few grams up to 5 kg, with lengths ranging from 50 to 800 mm and thicknesses that, in some cases, do not exceed 0.5 mm.
The Wax Department is equipped with a series of semi-automatic systems for injecting wax into steel/aluminum molds to produce wax models of the final components. These systems ensure the control and monitoring of thermal, fluid, and dynamic parameters throughout the entire wax injection process. In particular, the main variables of the injection process are continuously monitored via sophisticated feedback systems to ensure process stability, thereby guaranteeing full compliance with established standards and high product quality at all times.
The wax models produced in this way are then hand-finished on workbenches equipped with state-of-the-art equipment for finishing and preparing them for the subsequent stages of the production process. Subsequently, the wax models undergo a series of non-destructive tests, such as visual inspection, digital radiography, dimensional measurements using CMM machines, optical scanning of the entire wax model using the latest generation of GOM blue-light cameras, and wall thickness measurements with ultrasonic machines to verify compliance with quality standards. The wax models are then assembled in varying numbers, depending on type and size, onto specific clusters to increase process efficiency in terms of raw and auxiliary materials as well as productivity.
The thermo-hygrometric conditions in the Wax Area (temperature and relative humidity) are continuously monitored to ensure the dimensional stability of the components while they are in the Area.
Ceramic Shells Section
The Ceramic Shells Division is equipped with six robotic cells for the automatic application of ceramic layers to produce high-performance shells.
Robotic cells ensure a high degree of operational flexibility for the production of a wide range of shells in terms of:
- Materials – Three different ceramic shell systems are available, with mechanical properties capable of meeting the casting requirements for all types of alloys used in EMA and for the three solidification processes: directional (DS), single-crystal (SX), and equiaxial (EQX);
- weight - up to 150 kg;
- Dimensions—maximum cylindrical dimensions of 1,000 mm in height and 800 mm in diameter.
The robots provided are state-of-the-art (6/7-axis anthropomorphic robots) and enable precise and gentle (vibration-free) handling of both small and large wax clusters. All rotating tanks containing ceramic slurry are equipped with automatic lids and cooling paddles to prevent contamination and maintain the slurry temperature under control, respectively.
The plaster distribution chambers—whether rotary or vertical—ensure uniform distribution of the plaster powder over the clusters.
All ceramic mixtures are prepared using an automatic mixing system that automatically transfers and mixes the various constituent materials (e.g., binders, refractory powders, wetting agents, and defoamers).
All ceramic slurries are regularly monitored during production by measuring various physicochemical properties (e.g., viscosity, opacity, temperature, pH, total solids, silica content, specific gravity, and gelation tests).
The particle size distribution of the plaster powders received is regularly checked.
To ensure the stability of the ceramic shell forming process, the control systems in the department use complex feedback systems to ensure:
- comprehensive management of robot programs in terms of motion (rotation, translation, and duration of individual movements);
- the control and monitoring of all process and environmental parameters, such as dough temperature, ambient temperature and relative humidity, and airflow velocity within the rooms used for forced drying of the shells.
Ongoing development activities are carried out to select new, increasingly high-performance materials and new in-line measurement tools for the physicochemical properties of the materials used in the forming of ceramic shells.
Ovens Section
The Ovens Area is divided into two main sections:
- preparation for casting, where the following operations take place:
- Internal cleaning of ceramic shells using vacuum and washing techniques to ensure the complete removal of anything (e.g., debris) that could potentially cause metallurgical defects
- Checking the integrity of ceramic shells using tracers capable of detecting even the most imperceptible cracks
- Application of insulating pads to the ceramic shells of equiaxial solidification (EQX) components, with dimensions and shapes ensured by CAD/CAM-controlled cutting.
- merger.
There are three types of equipment used for casting, which is the very heart of the manufacturing process:
- High-vacuum resistance furnaces for the manufacture, through a Bridgman-type controlled solidification process—either single-crystal (SX) or directional-grain (DS)—of small components weighing up to 10 kg per casting;
- High-vacuum induction furnaces for the manufacture, via a “tilt pouring” process, of components weighing up to 70 kg per pour and featuring an EQX structure; Each furnace is fed by a dedicated, dual-zone preheating furnace capable of ensuring high thermal uniformity (±10°C);
- High-vacuum induction furnaces for the manufacture of large components using a process involving:
a. Bridgman-type controlled single- or multi-crystal solidification of components weighing up to 60 kg total per casting;
b. “Tilt pouring” for EQX solidification components weighing up to 100 kg per pour.
All plants are equipped with feedback systems for monitoring and recording the key process parameters of each casting (e.g., vacuum level, temperature, electrical power, pouring rate, extraction rate). The integrated recording system also ensures access to ongoing operations from any computer workstation within the company and the ability to monitor, at any time, the key parameters of each casting and, if necessary, correlate them with any other parameters of the company’s production process and with the results of the scheduled non-destructive tests.
Post-Cast
The POST-MERGER (POST-CAST) area consists of the following cells:
- FINISHING (DRESSING) is performed using belts with a cloth backing and coarse abrasives designed to remove material from the surfaces. Subsequently, to reduce roughness, nylon-fiber belts impregnated with fine abrasives are used. The purpose is to remove marks left by previous processes and by post-finishing dimensional (DIM) and non-destructive testing (NDT) inspections.
- HEAT TREATMENT in high vacuum to modify the material’s properties as requested by the customer; some components are also subjected to ultra-high-pressure heat treatments (up to 1,300 atm) to eliminate any internal shrinkage caused by the cooling of the molds after casting; the systems used for these treatments are equipped with computer stations for controlling, monitoring, and recording all process parameters, such as pressure, temperature, and time
- CHEMICAL TREATMENTS to prepare the surface for subsequent inspections; components with a ceramic core undergo leaching processes in an autoclave using aqueous caustic soda solutions under controlled pressure and temperature cycles; the solutions used in these processes are regularly monitored and, if necessary, adjusted or discarded based on the results of analyses conducted by the EMA Laboratory
- SURFACE TREATMENTS, such as shot blasting, glass bead blasting, aluminum oxide blasting, and cleaning, performed to prepare the surface—in terms of cleanliness and roughness—for subsequent processes
- MARKING is performed using a vibrating tungsten carbide-tipped stylus, powered pneumatically or electrically, which generates micro-impacts on the surface without producing chips or waste material. The purpose is to uniquely identify components.
Simulation of the lost-wax investment casting process
Simulation of the lost-wax investment casting process is used at EMA to support two key processes in production engineering:
- - Introduction of new components through research and the identification of the optimal and robust combination of key process parameters, thereby reducing the time and cost required for component development;
- Continuous improvement through yield optimization and cost-reduction initiatives.
This process is used in the production of components with directional, single-crystal, and equiaxed grain structures.
The heating and filling of the ceramic shell and the solidification of the melt are simulated using finite element analysis (FEM) with the proprietary QM00 software and the commercial ProCAST software. This approach identifies the risks of thermally and mechanically induced defects specific to each modeled process configuration.
Simulation allows for the development, testing, and optimization of various process methods in a virtual environment, thereby reducing the number of physical casting tests by varying and testing elements such as:
- geometry of the component and the core;
- assembly geometry;
- shell material and thickness;
- type of alloy;
- merger plan.
Checks
100% of production parts undergo metallurgical and dimensional inspections to ensure compliance with the requirements of the applicable drawings and specifications.
The category of metallurgical inspections includes NDT (penetrant testing, visual inspection, and X-ray testing) and grain structure inspection, a non-destructive method used on metallic materials to verify structural indications that appear on the surface as a result of selective galvanic corrosion, in an environment illuminated by visible light. The visual method for grain inspection allows indications to be highlighted through contrast.
Dimensional inspections include pass/fail tests (profile scanning, gauges, clock gauges, etc.) and inspections using coordinate measuring machines (CMM) and structured light (GOM) systems. Furthermore, when cooling channels are present, wall thicknesses are verified using ultrasonic techniques.
For specific components, additional tests may be performed, such as measuring air or water flow rates, inspecting cooling channels, conducting conductivity tests, etc. The high-precision machines used for dimensional inspections, together with equipment that undergoes periodic visual and metrological checks, ensure the production of components of the highest quality.
Laboratory
The EMA laboratory is equipped with all the necessary equipment to perform metallographic and chemical tests on products and production processes in order to meet validation and production control requirements, as well as to investigate and identify the causes of any anomalies. Both metallographic and chemical analyses are Nadcap-accredited and approved by our customers. All mechanical tests are performed by approved external laboratories.
The main pieces of equipment used for metallographic analysis are:
- Cutting Machines
- Incorporators
- Automatic Grinding and Lapping Machine
- Optical microscope with a CCD camera and image analysis system
- Stereo microscope with a CCD camera and image analysis system
- Scanning Electron Microscope with EDX Probe
The main pieces of equipment used for the chemical analysis of alloys are:
- XRF Spectrometer for the Analysis of Major Elements
- Microwave Digester and ICP-MS Spectrometer for the Analysis of Residual and Trace Elements
- Analyzer for the determination of carbon and sulfur by combustion
- Analyzer for the determination of nitrogen and oxygen by fusion
The main equipment used for the chemical and physical analysis of the other materials is as follows:
- Titrators designed for ceramic leaching solutions, for acid etching prior to grain inspection and testing with penetrating fluids, for neutralization, and for cleaning and degreasing.
- Furnaces, muffle furnaces, balances, and pycnometers for analyzing total solids, density, and binder solids in ceramic mixtures.
- Centrifuge and portable XRF spectrometer for analyzing the silica content in the binder of area shell mixtures.
- Sieves and an optical particle size analyzer for the particle size analysis of flours and ceramic powders.
- Optical dilatometer for measuring deformation in ceramic specimens.
- Water-based autoclave for porosity measurements on ceramic samples.
- Thermogravimetric analyzer with simultaneous differential scanning.
- Adhesion testing machine for ceramic materials.