On the Elevated-Temperature Strengths of Some Aluminium Cast Alloys for Piston

Abstract

Table I and II, respectively.The specimens were cast into a permanent mould which is in accordance with Japanese Industrial Standard (JIS) H0321.The alloys were compared on the basis of their tensile properties at elevated-temperature after 1000 hour soaking. The creep tests were carried out with the lever-type creep-rupture tester, and the creep strengths were calibrated at 0.1% per 1000 hours.The fatigue tests were conducted on Ono's high-temperature fatigue tester (3000rpm) and fatigue strengths were determined at 107 cycles.The fatigue strength showed lower value at the temperature ranging from room-temperature to and T5 treatment showed slightly higher strengths than by other treatments at further elevated-temperature. The authors would recommend T5 treatment for the heat-treatment of those alloys for piston.The strengths of nickel-free alloys decreased a little compared with nickel-containing alloys at elevated-temperature.It would appear from the above results that elimination of nickel from the alloys is undesirable. Alcoa F132, however, which has a reduced nickel content of less than 0.50%, is currently in use in U.S.A., and in consideration of the difference in strengths of nickel-free and nickel-containing alloys, it may be acceptable for nickel content of these alloys to approach the lower limit of the current specification.

The Effect of the Connectivity of Rigid Phases on Strength of AlSi Alloys

“…They exhibit not only a relatively high elevated temperature strength but resist as well thermal fatigue, which indicates a composite‐like behaviour with load transfer from the Al‐matrix to stiffer intermetallic phases. It has been reported that Ni improves the high temperature strength of AlSi alloys36 due to the presence of Ni aluminides such as Al 3 Ni and Al 9 FeNi 37–39. The effect of 1 wt% Ni addition on the architecture, strength and thermal cycling creep resistance of an AlSi12 alloy was investigated in ref 40, 41…”

Three-dimensional rigid multiphase networks providing high-temperature strength to cast AlSi10Cu5Ni1-2 piston alloys

“…This spheroidization of the eutectic Si limits the use of AlSi12 cast alloys for high-temperature applications. The addition of transition elements such as Ni and Cu are considered to be an effective way to improve the high-temperature strength of cast Al–Si alloys in as-cast and solution-treated conditions by forming stable aluminides [10–15] . Recently, we have shown that the higher high-temperature strength exhibited by AlSi12Ni as compared to a Ni-free AlSi12 alloy is conferred by a highly interconnected 3-D structure formed by 20 vol.% of eutectic Si, Al 9 FeNi and Al 15 Si 2 (FeMn) 3 aluminides [9] .…”