Creep feed grinding wheels combine high performance with long life

Citation

(2008), "Creep feed grinding wheels combine high performance with long life", Aircraft Engineering and Aerospace Technology, Vol. 80 No. 1. https://doi.org/10.1108/aeat.2008.12780aad.002

Creep feed grinding wheels combine high performance with long life

Creep feed grinding wheels combine high performance with long life

A new generation of highly porous, vitrified wheels for creep feed grinding has been introduced by Tyrolit, which claims users will see a 30-50 per cent productivity advantage over conventional products, leading to dramatically reduced component costs.

Called Strato-Ultra, the wheels use a high-strength bond that allows the amount of vitreous material to be reduced, which in turn allows the abrasive grain content to be lowered. The results are an increase in both pore volume and average distance between individual grains, delivering a creep feed wheel that holds profile better and for longer (Figure 1).

In operation, friction is lower due to fewer cutting edges being in contact with the workpiece. There is also less bond material in the contact zone, which can inhibit chip removal and cause additional friction. As a consequence, the amount of heat generated is said to be reduced, forces on the component are lower, and the power drawn by the drive motor is decreased.

Figure 1 Tyrolit's new Strato-Ultra AlOx wheels for creep feed grinding hold form well, despite having less bond material for a given volume and more widely dispersed abrasive grains

These benefits are thought to improve component quality, both dimensionally and metallurgically, as well as speeding grinding cycle times and resulting in a more efficient and economical machining process.

Despite being very porous, the wheels exhibit considerable mechanical strength even for large diameters and wheel widths, allowing relatively high- peripheral grinding speeds up to 63m/s, without the need for additional bore reinforcement. They are said to be especially well suited to VIPER grinding of gas turbine engine components, with or without continuous dressing.

Tyrolit continues to recommend that fused aluminium oxide (AlOx) grain is the preferred type for most aerospace and turbine applications. While there can be some benefits from using sintered grain in certain applications, the negative effects of high-wheel cost, high-diamond roll wear and poor process capability when producing deep profiles, results in a majority of users staying with fused-grain wheel types.

The case for fused AlOx grain is said to be further strengthened by Strato- Ultra itself, as the extended wheel life and lower grinding forces allow users to realise most of the benefits normally associated with sintered-grain wheels, without the above disadvantages.

Strato-Ultra wheels are environmentally friendly to produce, as the firing temperature is less than for other creep feed bonds and the overall firing time is reduced, resulting in reduced energy consumption during manufacture.

Details available from: Tyrolot Ltd, Tel: +44 (0) 1788 824500, Fax: +44 (0) 1788 823089, E-mail: john.willis@tyrolit.co, web site: www.tyrolit.com