High-Performance Cast Aluminum Pistons for Highly Efficient Diesel Engines

Micromechanisms of short fatigue crack growth in an Al–Si piston alloy

“…Previous studies [1,3,7,8] on model piston alloys with high Cu and Ni levels (3.9 wt.% Cu and 2.8 wt.%Ni) confirmed that fatigue crack initiation occurs at Si particles and intermetallic particles such as Al 9 FeNi and Al 3 (CuNi) 2 . Some of the model alloys investigated contained reduced Si levels of 6.9 wt.% and 0.67 wt.% as shown in Table 1.…”

“…The rapid increase in performance requirements in diesel engines together with light-weighting and strict emission regulations has necessitated development of new piston designs and materials that can withstand the increasingly harsh combination of fluctuating thermal stresses and cylinder pressure [2,3]. As a result, new alloys have been developed with increasingly higher levels of various alloying elements such as Cu to upwards of 4-5 wt.% and Ni to ~3 wt.% [3,4].…”

Effect of intermetallic particles and grain boundaries on short fatigue crack growth behaviour in a cast Al–4Cu–3Ni–0.7Si piston alloy

“…) in the hipped and unhipped conditions. Figure a shows the piston casting mould configuration used by the manufacturer to ensure laminar and quiet melt flow conditions during filling . During mould filling, the melt has to pass through a ceramic foam filter before being fed into the die cavity from the bottom.…”

“…This casting process with a ceramic filter and bottom ingate results in a cast structure that is consistently low in oxide inclusions. 54 The hipped pistons were supplied after being subjected to a hipping and heat treatment procedure involving holding at 490 °C and 100 MPa for 4 h, solution treatment at 480 °C for 2 h, a water quench and finally ageing for 8 h at 230 °C. The unhipped pistons were supplied after aging at 230 °C for 8 h. The microstructure of the hipped and unhipped versions of this alloy has been characterized in detail as documented by Moffat 13 and Mbuya.…”

Durability and reliability in diesel engine system design

“…The calculation of piston temperature distribution was conducted theoretically by Woschni (1979) and numerically by Wu and Chiu (1986). For more information on diesel engine piston structural calculation, design, fatigue life, material, and durability analysis, the reader is referred to the following: Makartchouk (2002), Munro (1999), Spengler and Young (1986), Myers (1990), Keribar et al (1990), Afonso et al (1991), Myers and Chi (1991), Castleman (1993), Vertin et al (1993), Barnes and Lades (2002), Reichstein et al (2007) and Cha et al (2009).…”