Towards the future of titanium machining with carbide specialist CERATIZIT
New carbide grade CTC5240 makes up to 20% higher cutting speeds and enormous cost savings possible
Once again carbide specialist CERATIZIT acts as a supplier of solutions in an innovative segment, namely titanium machining. Today CERATIZIT - with the new carbide grade CTC5240 - already accepts the challenges of the future.
The background for this is the demand for weight reduction in the construction of modern aircraft in both civil and military aviation. The industry sector responds to this requisite with new materials such as carbon fibre. In this context titanium is also gaining ever more importance in aircraft construction. Structural components which are held together by carbon fibres are ever more frequently produced in titanium – they form the base structure of a modern aircraft. Due to this tendency, structural components made of aluminium are being reduced in importance.
Accordingly, the number of component suppliers for the big aircraft constructors who have to face the difficult to machine titanium is increasing. In this context the new CERATIZIT grade CTC5240 helps, as it is heat resistant, tough, wear resistant and provides improved chip formation when machining titanium. In addition the new carbide grade CTC5240 makes up to 20% higher cutting speeds and enormous cost savings possible.
Consensus among the CERATIZIT employees involved in development: “Upgrades of existing grades and geometries are generally not sufficient.”
The CERATIZIT specialists have therefore made it their goal to offer the industry a tooling solution which allows high productivity and relatively low production costs for components made from such challenging materials as titanium. This was only possible by developing tools and inserts with excellent performance in terms of tool life, cutting parameters and process security. It is generally not sufficient to upgrade existing carbide grades and geometries to reach this goal. This is why the CERATIZIT team has been concentrating on developing a completely new combination of cutting material, coating and geometry, adapted exactly to the special challenges of titanium alloys right from the start. The following was required:
- a new carbide substrate with excellent heat resistance properties
- a new coating with sufficient toughness, high wear resistance and a small coefficient of friction
- new geometries for improved chip formation in the titanium
Titanium has a lot of advantages, but machining is costly
The advantages of titanium alloys compared to other materials are obvious. Titanium alloys are mainly characterized by low density which is only a little more than that of aluminium. Simultaneously they show twice as high a strength so that structural components can be designed slimmer and with lower weight. A disadvantage is their bad machinability which has a negative impact on manufacturing costs due to low cutting speeds and short tool life.
The most important reason for this bad machinability is the extremely low thermal conductivity of titanium alloys. Titanium conducts heat about ten times worse than steel. Contrary to the machining of steel the heat produced during the cutting process is therefore not evacuated with the swarf, but the major part of the heat is concentrated inside the tool or the cutting edge.
New grade CTC5240 is heat resistant, tough, wear resistant and provides improved chip formation when machining titanium
This is where CERATIZIT gets things moving. A carbide grade with substantially increased heat resistance was developed. The main advantage of the new CERATIZIT grade CTC5240 is really its high heat resistance, which allows cutting speeds up to 20% higher than comparable products from competitors. And this saves costs.
The recently developed grade which is to protect the carbide substrate against abrasion also serves as a heat barrier. This means the coating itself must have low thermal conduction properties to prevent the heat from reaching the carbide. In order to minimise the heat generation, it is essential that the coating has the smoothest possible surface and the swarf can glide over the rake face without substantial resistance. The recently developed TiB2 coating by CVD from CERATIZIT totally fulfils these specifications.
The extremely heat resistant substrate of the new CERATIZIT grade CTC5240 allows the application of inserts with an excellent cutting geometry. In this way cutting pressure is reduced which also limits heat generation, and chip formation is greatly improved through these extremely positive geometries. Additionally, compressed and lamellar chips are avoided, i.e. the cutting pressure and subsequently wear is reduced.