DLC innovative surface technology with outstanding features

MISUMITECHNOLOGY

The CO2 emissions from cars must drop to 95 grammes per kilometre by 2025, this was already decided by the EU member states in the year 2015. There are some starting points to realise this goal. Firstly of course the switch to electric vehicles, but also the reduction of the overall weight of vehicles plays a major role in the compliance with the limits for CO2 emissions. On average, the body makes up about one third of the total weight of vehicles. A great deal of work and experimentation is currently taking place with composite materials, such as glass or carbon fibre. These materials are currently still very expensive due to the complex manufacturing and processing. Aluminium provides an excellent compromise here between weight and expense and is increasingly being incorporated in body of vehicles. In the manufacture of vehicle chassis made of aluminium, however, there is a problem because the material aluminium does adhere to steel. Due to these manufacturing problems, the individual chassis components cannot be positioned correctly and there are problems in connecting the different frame parts in the body shell. Often production outages are the consequence here, which of course are to be avoided. DLC-coated locating bolts are one solution here.

A DLC (diamond-like carbon) surface coating is produced in a method of chemical (CVD) or physical (PVD) vapour deposition. This happens largely in a vacuum. There these are deposited as thin layers in layer thicknesses of a few micrometres. DLC layers may generally be applied to a variety of different materials. The prerequisite here is that these materials must be compatible with the vacuum required for the production of DLC. In addition, all components to be coated should be electrically conductive. The properties after coating speak for themselves:

  • Extreme hardness
  • Abrasion resistance
  • Low friction coefficient
  • Chemical resistance and biocompatibility

Components with DLC coating are used, for example, in automotive technology in the internal combustion engine or in thermoforming, extrusion and forging tools, but also as described above in automotive welding and assembly lines. For the intended purpose of body-in-white production, MISUMI offers DLC-coated locating pins with large or small heads with the following surface properties:

  • Good adhesion
  • Surface Hardness: ~ 3000 HV
  • Surface colour: Rainbow
  • Layer thickness: ~ 0.2 - 1.0 µm
  • Friction (steel): 0.15 - 2

The service life with DLC-coated locating pins from MISUMI is more than 50,000 cycles in automotive welding and assembly lines compared with a steel pin, which must be replaced after approximately 2,000 cycles.

Minimal wear enables increased production

 

Approx. 10 min. is spent cleaning each day during production on a positioning pin in order to remove cold welding on the pin with aluminium components. This is also the case with abraded aluminium chips which occur as a result of the high level of roughness on an uncoated steel bolt. The DLC coating ensures very high hardness and very low surface roughness and prevents cold welding of the aluminium components.

This graph clearly demonstrates how a 10 min. downtime of the production line each day and a decreasing number of cycles impacts the number of vehicles that are not produced. If you have a cycle time of 70 sec. and a downtime of 10 min. each day for example, you will produce approx. 1900 fewer vehicles each year. This can be prevented with our DLC coating and we have already gained positive experiences with a major German OEM during the production process.

So you save time and money in the future with locating pins from MISUMI!

 

If you have any questions about surface coatings, simply get in touch with our Technical Support at:

Email: mail.tech@misumi-europe.com