Life tools

Tonquin [61415-11-0] Tonquinmusk Tool life Tool materials... 

Tool life tests are used to evaluate the effects of changes in tool materials, cutting variables, processing history, workpiece composition, or workpiece microstmcture. Tool life, T, and cutting speed, can be related by the following equation ... 

Cutting fluids provide benefits such as extended tool life, dimensional accuracy and good surface finish, all of which contribute to high rates of production. Almost invariably, the coolant that adheres to workpieces is relied on to protect ferrous components against corrosion while they are waiting further machining or assembly operations. 

Poor maintenance practices lead to dirty and degraded coolant, which affects tool life, surface finish and perhaps the welfare of the operator. Proper filtration is vital, and care must be taken that contamination from other coolants or machine lubricants is kept to a minimum. 

Delliarciprete, J., et al, Cavity Pressure Transfer Extends Prototype Tool Life, MP, Jan. 2000. 

The shift from straight oils to synthetics has resulted mainly from machine improvement and increased restrictions on the disposal of oil and grease. Thus, metalworking fluids have been modified with water to minimize disposal problems and with chemicals to preserve the fluids and to accom modate higher speeds while increasing tool life. 

The stream flows on top of the chip and over the shank of the tool between work and tool holder but examination of the work face leaving the tool edge shows it to be bright and dry—no oil on it. Another proof that the tool edge is dry is found in build-up. Feathers and slivers from the cut collect on the upper edge of the tool and weld there. This build-up is responsible for much of the variation in tool life, since it varies greatly between tools. 

The authors have devised a new method of application that gives astonishing results. Instead of increase of tool life of 50 to maybe 150%—all they have hitherto been able to accomplish between different cutting liquids—increases of 500 to 800% at the same cutting speed are being obtained or the cutting speed can be doubled with the same life. 

The abrasive effect of treatments with inorganic salt crystals can reduce tool life. Where machining is necessary, this can be minimized by using tools of abrasive-resistant alloys. 

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