Additive manufacturing in metalworking

Brake caliper for a Bugatti, additively manufactured with machines from SLM SolutionsAfter two years ago, two large halls were already reserved for additive manufacturing (AM) at EMO, this year's edition of the trade fair in Hanover saw even more exhibitors from this branch of manufacturing. Machine tool manufacturing is one of the areas that will experience the greatest upheaval in the future due to additive manufacturing processes. We will give a brief outline of the innovations and trade fair highlights. By Sabine Slaughter

The market in the machine tool sector seems to be slowing down, explained Dr. Roland Feichtl, President of Cecimo, the European association of the machine tool industry and related manufacturing processes at EMO, in his keynote speech. This was partly due to the increasing difficulties on the international political scene. However, Cecimo manufacturing companies improved their productivity through continuous investment in advanced digital systems and highly innovative technologies, "even though the economic prospects seem unclear".
Before the end of the year, the focus will be on additive manufacturing at European level. The European Commission should soon publish a new study and guidelines on intellectual property rights and product liability to re-launch the debate on some important aspects such as quality standards and the difference between business to business and business to consumer. CECIMO will address policy makers to avoid burdening the sector with unnecessary regulations. This was stated by Stewart Lane, Chairman of Cecimo's Additives Manufacturing Committee at EMO. He noted that "the debate on the AM sector remains very active and EU policy makers need to establish a supportive and flexible regulatory framework if they want to maintain leadership of the AM sector in Europe".
Evo-Tech
The Austrian company brought both the EL-11 and the EL-102 to Hannover. The latter can support both individual and additive series production of products with eleven different engineering plastics, all developed by Evo-Tech. Linear axes with recirculating ball screws ensure maximum accuracy. Filament drying supports reproducibility and process stability while overdrying is avoided by means of a sensor. A water cooling system is also integrated. Two in one axis and dependent nozzles including cleaning station ensure a high quality print image. With each nozzle change, the nozzles can withstand up to 420°C, the entire melting zone is automatically changed, so that no mixing of the materials can occur. Components up to 500 x 400 x 510 millimetres can be printed in this way. Among the possible printing substrates are food-grade polymers for use in processing and packaging, electrostatically dissipative (energy-absorbing) plastics for the electronics industry and ASA (acrylic ester-styrene-acrylonitrile), which has high UV and weathering resistance in outdoor applications.
A novel FMP process (Filament Metal Printing), which is based on the MIM or PIM process, was developed for the production of metal and plastic components on the same machine. A green part is printed using metal-filled filaments. This is then debindered and sintered to produce a pure metal component.
GF Machining Solutions
The Swiss company presented a new look for its solutions at the EMO. These include the DMP Flex 350, developed jointly with 3D Systems, which is characterized by high repeatability, which is essential for the production of consistently high-quality parts. The machine delivers the purest atmosphere during printing: a constantly low-oxygen environment (less than 25 parts per million). This solution ensures excellent microstructures and a very high density. Its repeatable, stable mechanical properties give users the confidence to achieve consistent accuracy from job to job. High throughput 3D metal printing is ensured by the solution's fast, bi-directional material coating. At the same time, user productivity is increased through high printer utilization and short changeover times. Productivity is further maximized by optimized scanning strategies. The DMP Flex 350 is a robust, flexible 3D metal printing solution for 24/7 production of parts up to 275 x 275 x 380 millimetres in size and made of the most demanding alloys. According to the manufacturer, the machine is ideal for application development, production and research and development.
The company presented the new horizontal, high-speed wire EDM solution AgieCharmilles CUT AM 500. This fast, precise and automated machine is designed for metal finishing (AM) while maintaining geometric accuracy and ensuring readiness for assembly. It is a fast, precise and automation-capable alternative to the use of standard EDM or a band saw to separate additively manufactured parts from the building board. The CUT AM 500 complements the scalable, workflow-optimized 3D metal printing solutions DMP Factory 500, DMP Flex 350 and DMP Factory 350 from GF Machining Solutions and 3D Systems.
Visitors were already able to get a preview of the new AgieCharmilles CUT P 550 Pro, which is scheduled for market launch in mid 2020. It features a new man-machine interface (HMI) that promises intuitive operation and machine programming as well as flexibility. The company's new Spark Track technology is expected to provide a breakthrough in monitoring spark distribution along the wire by wire EDM. An intelligent spark protection system (ISPS) is designed to make the process safer, more efficient and easier, and to prevent wire breakage.
Under the motto "Passion for Education", the GF Machining Solutions Academy also presented new training modules and on-demand solutions for knowledge transfer at the manufacturer's stand.
Trumpf
The company demonstrated how additive manufacturing methods improve the production of heat-resistant materials. These often consist of the nickel-based alloy Inconel. The material can withstand temperatures of up to 1000 degrees without warping. The material is used, for example, in gas turbines, internal combustion engines or heating equipment. However, Inconel is difficult to machine using conventional methods. Milling tools often get stuck, break off or become blunt. At EMO 2019, TRUMPF presented how components made of Inconel can be manufactured faster, cheaper and with better quality using additive manufacturing.
Compared to machining processes such as milling or turning, a 3D printer does not waste any material because it only melts as much powder as the component requires. Manual reworking is hardly necessary, which considerably reduces tool costs. In addition, AM achieves better quality because complex shapes can be easily implemented. Internal cooling channels, which increase the performance and service life of the components, are easy to manufacture, says Trumpf. It is one of the few companies that also offers in-line finishing of printed products.
"Heat-resistant materials play a key role in many industrial sectors, including aerospace and energy. With our application examples at EMO, we want to encourage companies from these sectors as well as job shops to get into the technology," said Volkan Düğmeci, an employee in the aerospace industry management team at TRUMPF Additive Manufacturing. The TruPrint 3000 3D printer, which TRUMPF presented at EMO, is ideally suited for classic Inconel applications. Several parts can be produced simultaneously in the 40-centimeter high and 30-centimeter wide cylindrical installation space. The system also has solutions for automatic quality assurance, such as powder bed monitoring or melt pool monitoring. "In industries with high safety regulations such as aerospace, this is an important added value," said Düğmeci.
Trumpf showed, for example, an additive manufactured impeller for gas compressors made of Inconel. According to the company, conventional production takes eight days and consumes high tool costs. In addition, 80 percent waste is generated. Trumpf's additive manufacturing process reduces these negative variants to a production time of four days including reworking, whereby three impellers are manufactured simultaneously on one platform. The material loss is reduced to 20 percent. The printed gas compressor has the same quality as the original.
VBM Components
The Swedish company brought what it says is currently the hardest steel available: Vibenite 290, which has a hardness of 72 HRC (940-1100 HV). This material for additive manufacturing thus has very heat and friction resistant properties, which lead to exceptional hardness and load capacity. This makes it ideal for roll milling and dry milling applications, among others.
Renishaw
The RenAM 500Q four-laser system for additive manufacturing of metal parts was on display at the company's AM stand. The optical system and control software on the machine ensure that laser beams enter the system via four channels, where they are dynamically focused and directed into a single, thermally controlled galvanometer holder. This has four pairs of digitally controlled guide mirrors that guide the lasers to cover the entire working area of the powder bed. "Renishaw's additive manufacturing machines and optical systems are developed, designed and manufactured in-house, giving us exceptional control over system performance," explains Robin Weston, marketing manager in Renishaw's Additive Manufacturing Products Division. "An innovative optical system design, integrating digital controls and dynamic focusing, allows all four lasers to address the powder bed simultaneously - improving speed, productivity and machine performance".
The system builds on the safety and ease of use features of the RenAM 500M single laser and includes two SafeChange filters with automatic changeover to minimize manual intervention. Additional studies have shown that the powder condition is maintained for maximum reuse, further reducing part costs.