Influence of sic and graphite on tool life used in drilling C63200 alloy prepared by powder metallurgy

Abstract EN

Nickel-Aluminum Bronze (NAB) alloys have properties meet many requirements in engineering applications.

0T1TBut0T 1Tmany, especially the alloy C63200 suffer weakness in machining properties, so the current study aims at improvement the machine ability of this alloy without loss their mechanical properties.

A base 1Talloy of 1T (Cu-9 %Al-5 %Ni-4 %Fe) composition was prepared by compacting mixed powders of the constituents under a 0T1Tpressure of 656MPa and sintering at 950℃ for 50min in special atmosphere, 0T1T then 0T1Theated to 900℃ for 45min and quenched in water and then aged at 500℃ for0T1T 25min.

Under0T1T 0T1Tthe same conditions other 1Tsamples1T of the alloy with various percentage of graphite or / and SiC additions0T1T were prepared0T.1T The effects of these additives had been studied.

Machine ability was represented by a tool life 1Tof a1T 3mm-diameter high speed steel twist drill.

A maximum width of flank wear of 450μm was considered1T as a criterion of tool life.

Three cutting speed (0.95, 1.7, 3m / min) each with three feed rate (0.1, 0.25, and 0.4mm / rev) were considered as cutting conditions.

1TThe study showed that (0.6 %graphite) reduces the hardness by (11 %) and the porosity by (30 %), while (2 % SiC) increases the hardness by (14.7 %) and the porosity by (13 %).

Adding 0.6 % graphite and 2 % SiC together causes a decrease of (9.7 %) in porosity and an increase of only (1.2 %) in hardness.

A maximum 1Tincrease1T in tool life of (27 %) was achieved with an addition of (0.6 %graphite) while a maximum reduction of (29 %) was recorded due to (2 % SiC), but (0.6 %1T graphite) 1T with1T 1T (2 % SiC) caused an increase of tool life by (7 %).