Zhuhai CTC Electronic to launch SLM Metal 3D Printers
Leading Chinese 3D printer manufacturer Zhuhai CTC Electronic Co., Ltd, will host the “Wind from Southern China Press Conference for a Series of CTC Industrial 3D Printers” in Dongguan, Guangdong province, China on August 28. At the time, Zhuhai CTC Electronic plans to launch a series of new products, including the Riverbase 400 /500/600 industrial light curing printers and the Walnut 11/18/26 metal 3D printers
The SLM metal 3D printer, deploying the fastest growing technology in the industrial 3D printing sector, has been something the industry has been holding out high hopes for. The successful launch of Zhuhai CTC Electronic’s metal 3D printer demonstrated that the company has become the only full technology chain vendor in China’s domestic 3D printing sector, rivaling foreign competitors 3D System and Stratasys.
The Selective Laser Melting (SLM) technology is an important part of rapid prototyping. Zhuhai CTC Electronic’s SLM printer scans metal powder with granularities ranging from 20 to 60 micrometers using finely focused light spots, and can scan any shape. The printer features functional parts with the quality level that is equal to or near that of traditional metallurgical processing, with a compactness exceeding 98%. After reprocessing, the technology can meet 100% of the technical requirements, with a size precision reaching 20-50 micrometers and a surface roughness of 20-30 micrometers. As one of the most advanced additive manufacturing technologies in China, SLM can be used in molds and dies as well as in the automotive, pharmaceutical and aviation industries.
Zhuhai CTC Electronic’s Walnut series of printers incorporate a fiber laser, which is ideal for rapid prototyping as it is maintenance free and features excellent beam quality and high photoelectric conversion efficiency. Power ranges include 200W, 400W and 500W.
Laser scanning technology and process control
Zhuhai CTC Electronic’s SLM printer deploys single-weld prototyping, and its parts are formed by overlaying several mould surfaces. Each surface is woven with many single scan lines. The forming regulation for the overlay of single scan lines and single-mould surfaces made from power materials is the key to the compactness and tensile strength of the finished parts. Zhuhai CTC Electronic has been designing scanning paths and overlay solutions specifically for a range of materials that include titanium alloy, aluminum alloy, iron and nickel. The latest version has added 30-60 degree scanning in addition to the 90-degree scanning, providing an optimal scanning solution.
Energy input control
In general, high laser energy input can result in a smooth and continuous single weld. However, high laser power tends to gasify materials, which would not only reduce the material quality in the molten pool, but also scatter the power around the pool. As a result, power become insufficient to ensure a full molten pool for the next line of scanning. Zhuhai CTC Electronic has obtained the energy parameters for SLM prototyping of a multitude of materials through nearly 10,000 tests, and is able to set the range of energy input for super-fusion, semi-fusion and full fusion.
Prototyping scanning strategy
A fill-in scanning approach has a great impact on the compactness of SLM moulded parts, prototyping efficiency and the reduction of internal residual stress. Zhuhai CTC Electronic’s printers can provide different scanning velocities for the outline, internal layer and core of a part, achieving high compactness and surface quality through low-velocity scanning for part outlines and improving prototyping efficiency through high-velocity scanning for internal layers and cores.
Moulding process detection and feedback
During printing, control and detection of the oxygen content directly influence the smoothness of the prototyping and the safety of all of the equipment. Zhuhai CTC Electronic’s SLM printer closely monitors the oxygen content and temperature in the prototyping chamber, using an embedded operating system to automatically control air filtration velocity and an inert gas filling switch to ensure that the oxygen content in the chamber satisfies the requirements for the various materials.
Although the SLM technology in principle can mould metal parts into any complicated shape, it cannot perfectly mould all geometric features, including thin plates, sharp corners and especially dangling constructions. Zhuhai CTC Electronic’s Walnut SLM printers use the company’s proprietary support generation software to solve the issue.