PROGRAMME LIFE 13 ENV/IT/000593
The following technologies were used to achieve the objectives of the Life for life’s material project:
- The cryogenicprocess, through nitrogen, in the removal of material, for the production of clean waste: the gas, in fact, performs the functions of cooling the tool and the material being processed, of fast removal of swarf from the cutting area, as well as that of avoiding the oxidation of titanium caused by the high temperature that is generated during the processing. Moreover, by evaporating immediately after performing its function, it does not leave any residue on the processed material or on the resulting swarf. This technique therefore eliminates the use of emulsified water and coolant oils, avoiding washing with solvents and allowing the reuse of chips as they are.
- Two methods of metal sintering of the powders deriving from the same clean swarf, in pulsed current (SPS – Spark Plasma Sintering) and by means of microwaves, which have been used to test the possibility of obtaining, respectively, new products in massive and porous titanium, with significantly lower energy costs compared to those required by traditional metal remelting processes.
The main environmental benefits resulting from the implementation of the LIFE 13 ENV/IT/000593 programme concern the complete and easy recyclability of titanium swarf and the unnecessary use of lubricants.
Oxygen absorption as a result of recycling is low and several recycling operations for the same metal are possible.
LIFE 13 ENV/IT/000593 RESULTS
Therefore the important results of the LIFE 13 project ENV/IT/000593 are:
- Recycling of processed titanium swarf into porous products by microwave heating: >70% using recycled or new aluminium powders;
- Increase in the service life of cutting tools up to 40% longer than current values;
- Recycling of titanium swarf into dense products by SPS: 100%;
- Additional possibility of exploiting titanium swarf by milling and processing them into powders for powder metallurgy applications.
- Complete recycling of titanium swarf no longer contaminated with organic lubricant/coolants achieved without any treatment prior to sintering;
- This completely eliminates the use of lubricants and coolants or their emulsions in the machining of titanium;
- There is no need to clean the swarf, i.e. no use is made of soaps, detergents, pickling acids or processed components: the liquid nitrogen evaporates and returns to the air without polluting;
- This eliminates disposal charges for titanium swarf contaminated with lubricant/coolant.