Fine machining & optics

The "Fine Machining and Optics" develops the technologies required to manufacture and machine precision components. Our developments are driven by a thorough understanding of the underlying engineering principles which are transferred to industrial practice through our practice of addressing specific questions, using state of the art machinery and software techniques. The technology portfolio encompasses ultra-precision grinding and polishing, diamond machining as well as molding of high precision glass components, which we undertake from start to finish, beginning with tool design through to molding the finished optics.

We develop robot and machine-based grinding and polishing technologies for automated fine machining operations to replace operations which are still conducted manually in tool and mold making and in the manufacture of aero-engine components.

Optics

Fine Machining

  • Solutions for automating fine machining
  • Polishing technology
  • Ultra-precision machining
  • Grinding and honing

Precision Glass Molding

 

High precision glass optics can be manufactured economically via isothermal precision glass molding. This replicative manufacturing process is eminently suitable for particularly complex geometries such as aspheres, diffractive structures, lens arrays or freeform optics. We utilize a range of specially developed, optical, low-Tg glass types for challenging optical applications. In addition to these, infrared transmissive chalcogenide glass and fused silica / quartz glass can be used for precision glass molding. The primary advantage of the technique precision glass molding is the scalability of the production yield achievable by using multi-cavity molding tools or adopting a wafer-based manufacturing approach.

Our Services

  • Developing the entire process chain for replicative production of glass optics based on your drawing.
  • Scaling the yield of glass molding processes via multi-cavity tools or wafer-based production.
  • Analyzing, implementing and optimizing glass molding processes at your premises.

Non-Isothermal Glass Molding

In contrast to conventional grinding and polishing operations, non-isothermal glass molding can be used to manufacture complex glass optics and even micro-structured surfaces containing a number of different optical functional surfaces in one single process step. The short process times coupled with the absence of any need for finishing operations mean that the process is ideally suited to mass production. This ensures that the advantages of glass as a material are transferrable to the application you have in mind.

Our Services

  • Developing glass molding processes for the manufacture of affordable glass optics.
  • Investigating technical viability and the economic potential of glass molding for your glass products.
  • Analyzing, implementing and optimizing glass molding processes at your premises.

Simulating Glass Molding Processes

Precision glass molding is an efficient manufacturing process used in replicative production of glass optics with complex shapes. During precision glass molding, the influences exerted by a number of factors result in a shrinkage error. The Fraunhofer IPT has developed integrated, numerical simulation software, which can compensate this error in advance. Simulations are conducted in order to obtain an initial prediction of the glass shrinkage and an a-priori compensated design of the molding tools. The use of the simulation software can significantly reduce the time and cost entailed in tooling and molding.

Our Services

  • Simulation-assisted design of glass forming processes, focusing on preform and mold design
  • Measuring glass material properties relevant to the molding process
  • SimPGM – Simulation Software Tool for Precision Glass Molding with user-friendly graphical user interface

Coating Glass Molding Tools

Precision glass molding facilitates the manufacture of complex glass optics for sophisticated high-tech applications. The economic efficiency of this process depends mainly on the number of lenses which can be manufactured using one set of tools. However, the high thermal, mechanical and chemical loads occurring during the process frequently result in premature tool wear. Special protective coatings can prolong the service lifetime of molding tools, thereby increasing the economic efficiency of the process many times over.

Our Services

  • Developing application-specific PVD coatings for glass molding
  • Analyzing and characterizing wear-resistant coatings for glass molding
  • Investigating service life time of innovative coatings on a purpose-built glass testing facility

Solutions for automated fine machining

© Photo Fraunhofer IPT

We develop automated fine machining systems for the tool and mold making sector, for the manufacture of turbomachinery components and for medical technology. These systems allow the production of high quality surfaces with finish quality ranging from technical to high-gloss. Due to the diversity of applications for the fine machining processes "grinding" and "polishing" we focus on both robot-based and machine-integrated technologies in interdisciplinary projects with partners from industry and research.

Polishing technology

© Photo Fraunhofer IPT

The pre and fine polishing operations carried out on optical surfaces in a wide range of materials are affected by a high number of influencing factors. To predict the polishing results, an extensive understanding of the principles and mechanisms in the part- and material specific polishing operations are necessary.

The materials and the surface qualities determine the polishing systems and technologies, which are described by the predominant material removal mechanism (mechanical, mechano-chemical, chemo-mechanical). The desired geometries determine which machine and polishing procedures are needed. Here, a distinction is drawn between areal and zonal polishing.

We develop customized polishing technologies geared to your requirements for polishing operations and help you to achieve more efficient and more reproducible production of high quality surfaces.

Our services

  • Qualifying and benchmarking polishing system components
  • Assessing and selecting appropriate polishing systems
  • Optimizing polishing processes
  • Machine tool integrated polishing
  • Analyzing polishing defects

Ultraprecision machining

Ultraprecision (UP) machining is used for high-precision operations conducted on optical and mechanical parts made from diverse materials. The flexible processes permit the production of both rotationally symmetrical and non-rotationally symmetrical parts such as spheres, aspheres, freeforms and structured surfaces. Using special-purpose ultraprecision machines and air bearing spindles in conjunction with appropriate process strategies enables dimensional form accuracies of P-V < 250 nm and surface roughness values of Ra < 5 nm.

Fraunhofer IPT uses the technologies of UP grinding with diamond grinding tools and UP turning with monocrystalline diamond tools as well as ultrasonic assistance. The range of materials includes ceramics, tungsten carbide, various types of non-ferrous metals, steels, plastic and glass.

Our Services

  • Conducting feasibility studies and producing prototypes
  • Developing and qualifying machining processes
  • Machining of innovative and newly developed materials
  • Providing expert technological consultation