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Cu-9Ni-6Sn alloy has been developed as a possible substitute for high-strength, precipitation-hardened Cu-Be Fig. 1—Macroscopic views of (a) 90 pct hot-swaged Cu-6Ni-2Mn-2Sn2Al alloy and (b) 10 pct hot-swaged Cu-9Ni-6Sn alloy. alloys in the various applications of electronic industry.[1–7] However, it is often impracticable to produce sheet products from Cu-9Ni-6Sn alloy due to the severe cracking during hot working. It has been previously reported that Sn-rich segregates formed during solidification are responsible for hot cracking.[8] There have been considerable research activities to solve the hot cracking problem, including the powder metallurgy (PM) technique and the lowering of Sn content.[9] Powder metallurgy processed high Sn-containing Cu-Ni-Sn alloys can be readily rolled down to 0.2mm-thick sheet, but they have an inherent problem of high production cost. The previous study conducted by the authors has suggested that Cu-6Ni-2Mn-2Sn-2Al alloy is hot workable with a reduced production cost and reasonable physical properties compared to Cu-9Ni-6Sn alloys. The Sn content of 2 pct in the Cu-6Ni-2Mn-2Sn-2Al alloy makes it possible to be hot rolled to produce the sheet products. The Mn is isomorphous to Cu and can partially replace expensive Ni that is beneficial to castability and tensile strength. The addition of Al, which is a strong solid solution strengthener in Cu, compensates the reduced tensile strength as a result of lower Sn content. In conducting research, it was found that the addition of a small amount of Zr further improved the hot workability of Cu-6Ni-2Mn2Sn-2Al alloy significantly. The objective of the present study therefore was to examine the effects of beneficial Zr addition on the hot workability of Cu-6Ni-2Mn-2Sn2Al alloy. Cu-6Ni-2Mn-2Sn-2Al alloys without and with Zr addition of 0.3 wt pct were prepared using permanent mold casting in the form of either 25 mm round bar or 25mm-thick plate, respectively. A round bar with a 25-mm diameter was hot swaged at 850 8C to 8-mm diameter rod and air cooled. A plate with a 25-mm-thick plate was also hot rolled to 1-mm-thick sheet at 850 8C. Some specimens were aged at either 400 8C or 450 8C, respectively, for 1 to 7 hours. Tensile tests and Vickers hardness tests were conducted for selected specimens. Either a flat or cylindrical specimen, respectively, with a gage length of 25.4 mm was prepared from the rolled sheet or the swaged bar products, respectively. Bending fatigue tests were performed according to ASTM B593, using a Krouse-type bending fatigue machine, at an R ratio of 21 and test frequency of 20 Hz. Scanning electron microscope (SEM) and optical