Abstrait

Machining C-45 Steel With Cryogenically Treated and Microwave Irradiated Tungsten Carbide Cutting Tool Inserts

R.G.Deshpande

Tungsten Carbide tool inserts have excellent machining properties. But In machining of high strength temperature resistance alloys used in aerospace, marine and nuclear applications, they have failed miserably due to rapid wear. This has forced the machining Industry to bring in innovative changes in process design and application in terms of rigid machine tool and new cooling strategies. However, machining of these new classes of materials is still plagued by low productivity due to rapid wear. In the present work, uncoated Tungsten Carbide cutting tool inserts of geometry SNMG 120408-MR4 have been used. The inserts were cryogenically treated and were subjected to Microwave Irradiation. The inserts were placed on refractory brick, covered with charcoal powder and then heated for 9, 11, 13 mins. The inserts were left to cool to room temperature inside the microwave oven itself. he samples showed appreciable improvement in hardness and microstructure study revealed that carbide phase distribution was fairly uniform with binder phase segregating slightly in few cases. Under all cutting velocities, Cryo-treated and microwave irradiated inserts showed the highest tool life and wear resistance. Microwave heating has significant influence on the phases present in WC+Co inserts and subsequently influences their machining performance.