Executive Summary : | Objective: Establishing a niche process chain of manufacturing and metrology for laser assisted ductile mode machining of hard ceramics and metallic alloys with ultra low surface roughness (Ra < 10 nm) and high form accuracy (deviation < 150 nm) Performing a detailed parametric optimization study for achieving optimal combination of surface finish, tool wear and material removal rate for various hard ceramic and metallic alloy materials; Delivery of nanofinished ceramic and metallic (nickel, tool steel and titanium alloy) based components (moulds, ceramic race, cups for hip joint prosthesis etc.) for material forming, automotive and biomedical applications Summary: Ceramics are materials of choice in applications where the requirements of low surface wear, high hardness, high compressive strength, high thermal fatigue and high resistance to corrosion and erosion are of prime concern. Despite these advantages, fabrication and industrial application of ceramic components in high end engineering are relatively limited primarily due to their poor machinability in comparison with metals and alloys. This may be attributed to the brittleness and low fracture toughness of ceramics. Unlike ductile metals and alloys which can be machined by CNC turning lathe in a cost effective manner with a high rate of material removal, ceramics are usually machined by grinding and lapping which is a much slower process than turning due to low material removal rate and adds to the cost of the fabricated component. Moreover, grinding and polishing yield a relatively rough surface of Ra in the range of tens or hundreds of microns. In this proposal, it is envisaged that a multi-step strategy of fabrication of ceramic and hard alloys will be adopted comprising electro-discharge machining, magnetorheological abrasive fluid forming and ductile mode laser assisted ultra precision CNC machining of ceramics. The last named technique is a novel methodology which has been established first time in the country at CSIR-CGCRI which can yield nanofinished hard ceramic and alloy surfaces with ultra low roughness of upto 10 nanometer or less by allowing laser beam to locally soften the ceramic ahead of the tool enabling ductility during machining of brittle ceramics. CSIR-CGCRI will utilize its niche expertise/technology in this area to further optimize the technique for various types of oxide and non-oxide ceramic materials, including ultra-high temperature ceramic components and specialty optical glass which are important for strategic, biomedical, automotive and societal applications. The process chain developed in this project will eventually lead towards translational activity after completion of the current project tenure by handholding with industrial partners, such as, Bharat Electronics Ltd., Bharat Heavy Electrical Ltd., L&T Defence etc. |