Renishaw SLM (Selective Laser Melting) is a pioneering additive manufacturing process capable of producing fully dense metal parts direct from 3D CAD using a high-powered fibre laser.
Parts are built from a range of fine metal powders that are fully melted in a tightly controlled atmosphere, layer by layer in thicknesses ranging from 20 to 100 microns.
The current machine range comprises the SLM250 and the SLM125, both of which feature vacuum technology and low gas consumption. The machines have been designed for ease of use within a manufacturing environment and feature a touch-screen interface and various menu options for machine preparation and clean down.
Machine robustness has been given high priority, adopting a 'machine tool' approach to use and serviceability. Consumables costs are minimised through careful design and features, such as the soft re-coater blade that can be rotated several times before replacement and the use of low-cost filter elements, right through to low gas consumption — all contributing to system reliability and low cost of ownership.
Renishaw's SLM systems have always processed a wide selection of materials and the new range is no exception, which support this via rapid materials changeover on the SLM125, courtesy of a cassette type materials delivery system, and, on the SLM250, by a removable hopper - particularly useful where materials development or a range of materials are in use.
The capability to safely process reactive materials such as titanium and aluminium is a standard feature on MTT SLM machines. In particular, the gas knife that clears away reactive sooty emissions and the heated build plate are both pre-requisites for the successful processing of both materials.
Both the new machines feature a fully welded vacuum chamber, enabling low-pressure evacuation followed by a recharge with high purity argon gas. The gas consumption rate, after the initial chamber flood, is extremely low and allows operation at oxygen concentrations below 50 parts per million — a crucial factor when processing reactive materials such as titanium and aluminium; and contributing significantly to material integrity and mechanical performance.
All machine program preparation is completed off-line through a choice of interface, either Marcam Autofab software or via Materialise Magics. Once complete, the build file is uploaded to the machine via a secure network or direct connection. Product traceability has been improved by the addition of process data and event logging as standard, with various additional process control options on request.