Hello kumar,

The selection of a proper tool material depends upon number of factors such as type of machining operation, material of the work piece, machine tool to be used and surface finish. As you are going for aluminum alloy with high strength you may go for HSS material of molybdenum group M7 (S400) since the percentage of molybdenum is more it is good resistance and high toughness material.

Good luck

If you have a good machine tool, the best tool material is PCD (Poly Cristalin Diamond).

Here you have a guide to solve your problem:

https://www.walter-tools.com/SiteCollectionDocuments/wmc/index-bakup.html#content/turningOp/material

Dear Sir,

PCD tool is most preferred in machining of Al alloy and in composite machining.

u can refer for detail about PCD tool in the following papers.

Conference Paper Study on Microstructure and machining characteristics of 7% ...

Article Influence of particle size on Cutting Forces and Surface Rou...

Thanks and Regards

PV Badiger