Path Calculation of 7-axes Synchronous Quasi-Tangential Laser Manufacturing

Quasi-tangential laser processing, also called laser turning is increasingly applied for various applications. Specifically, its ability to generate complex geometries with small feature sizes at high precision and surface quality in hard, brittle and electrically non-conductive materials. Due to the geometric flexibility, the process is well suited for prototyping in hard-to-machine materials such as ceramics, carbides and super-abrasives. However, the lack of advanced software solutions for this novel process hitherto limited the exploitation of the potential. Here, we discuss a unique computer aided manufacturing approach for synchronous 7-axis laser manufacturing with quasi-tangential strategies. This gives the peerless possibility to process arbitrary geometries, which cannot be manufactured with conventional techniques. A detailed description of the path calculation with derivation and procedures is given. The generated machine code is tested on a 7-axis laser manufacturing setup. Following, a processed cylindrical ceramic specimen with a continuously varying profile along a helical path is presented. The profile is constituted by a rectangular over half-spherical to a triangular groove with defined pitch, which provides the validation of this CAM solution. Measurements of the produced specimen show high adherence with the target geometry with an average deviation below 10 µm

Path calculation of 7-axes synchronous quasi-tangential laser manufacturing

ISSN:0268-3768ISSN:1433-301

Ultra-short pulsed laser conditioning of metallic-bonded diamond grinding tools

A novel approach for machining of cylindrical ultra-hard materials with a highly defined contour is presented. Diamond grinding tools with complex geometry are manufactured with picosecond orthogonal and quasi-tangential laser ablation. Hitherto, laser manufacturing required a special axis configuration and optical beam deflection devices are utilized. Here, strategies and processes on a scanhead-free configuration using ultra-short pulsed laser are discussed enabling straight-forward implementation in industry. This rapid and flexible approach for the production of master tools for industrial grinding processes reveals benefits compared to conventional techniques. The manufacturing time is comparable to standard processes, however, increased grain protrusion is attained with the presented laser sharpening strategy. An ablation study for maximal material-removal rate reveals the impact of wavelength, strategy, and repetition rate at high average power up to 100 W. A combined laser manufacturing routine enables an ablation rate of 35 mm3 min−1 and a maximal geometric deviation of 3 μm after finishing. The final grinding tools are sharpened by a radial laser process preferentially removing the metal-based binding material. Hence, high-precision diamond grinding wheels with a mean error of smaller 1 μm over millimeter-sized contours can be manufactured. The meta-stable diamond structure persists and is assessed via Raman spectroscopy studies at laser cut grains.ISSN:0264-1275ISSN:1873-419

Ultrashort-Pulsed Laser Machining of Dental Ceramic Implants

A novel approach for machining of cylindrical hard materials and arbitrary shapes is presented. Alumina-toughened zirconia dental implants with complex geometry are manufactured with femtosecond quasi-tangential laser ablation. This rapid-prototyping approach for small-scale production decreases the development-time cycle tremendously and trumps conventional approaches. Moreover, a competitive parameter study for radial and tangential ablation with single and multi-pulse is presented. A process achieving an ablation rate of 1mm3/min with a surface roughness Ra of 0.2 µm is introduced. The meta-stable tetragonal phase of the ceramic persists and is assessed via Raman spectroscopy. The small heat-affected zone is subsequently ablated with a radial laser process step. Hence, high-precision dental implants with a mean error of smaller 5 µm over the complete contour are shown

Ultra-short pulsed laser manufacturing of yttria stabilized alumina-toughened zirconia dental implants

ISSN:0277-786

CAM solution for quasi-tangential laser ablation of complex 3D workpieces

A fast forward computation of the laser ablation paths and hatches for complex 3D geometries enabled by a computer-aided manufacturing (CAM) toolbox is presented. Specifically, the laser paths for quasi-tangential irradiance condition on a rotary specimen are calculated and the machine code for a laser manufacturing system with up to seven synchronously controllable axes generated. In order to set the parameters for the path determination, an empirical parameter study points to the material specific removal rate in accordance with pulse and line overlap. Therefore, a manifold use of this tool is possible for all laser sources from continuous wave to ultra-short pulses. This leads to a unique flexible way, hith-erto not available for fast prototyping applications. Following, laser manufactured specimens with complex contour shapes reveal the high potential of this approach. High-precision laser manufactured dental implants and diamond-grinding tools with tolerances in the micrometer range serve as demonstrators

Ultra-short pulsed high-power laser conditioning of super-abrasive grinding worms Norbert

ISSN:0277-786

Ultra-short Pulsed Laser Marking and Coloration of Metals with Segmented Pixel Parameter Transformation

ISSN:1880-068

Innovative micro-tool manufacturing using ultra-short pulse laser ablation

ISSN:0924-013