Novel Sprue Designs to Reduce Casting Defects in Nickel-Aluminum Bronze: A Computational Study

Author(s):  
Philip King ◽  
Daniel Martinez ◽  
Guha P. Manogharan

Abstract As 3D Sand-Printing technology becomes more widely available to the casting market, the search for opportunities to take advantage of its freedom of design is critical for its rapid adoption by the casting community. This original research investigates casting design principles towards defect-free alloy Nickel-Aluminum Bronze (NAB). This is an alloy of interest for marine applications due to its corrosion resistance, mechanical strength and good castability. Numerical modeling of flow within a casting is examined, and rigging redesigns are proposed to improve casting quality by controlling flow behavior. It has been demonstrated that turbulence and filling velocity are determining factors that seriously impact casting performance due to the generation of casting defects. Among these are bifilm formations, gas and sand entrapment and cold shut. This work examines the effectiveness of mathematically designed rigging components in controlling mold filling and compares the results to a conventional casting rig. Design solutions are proposed using 3DSP that can be directly applied to casting operations of Nickel-Aluminum Bronze. The results from this study demonstrate the effectiveness of mathematically designed sprues to reduce filling velocity of Nickel-Aluminum Bronze. The procedure followed here can be extended to marine casting production environments. Findings from this study can be seamlessly transferred to castings of any geometry, alloy and pouring conditions.

1999 ◽  
Vol 5 (S2) ◽  
pp. 868-869
Author(s):  
J.C. Bennett ◽  
C.V. Hyatt

The copper alloys commonly referred to as nickel aluminum bronzes (NAB) are widely used in marine applications due to their excellent seawater corrosion resistance and good mechanical properties. Unfortunately, these alloys are susceptible to a variety of surface sensitive degradation processes such as cavitation and wear which significantly reduce service life. Laser surface melting and cladding techniques have recently demonstrated a potential to substantially enhance the performance of NAB components. This is associated with the occurrence of a martensitic or Widmanstätten transformation from the high temperature bcc β phase accompanied by precipitation of ordered intermetallic particles collectively referred to as κ. Optimization of these techniques requires an improved understanding of the evolution of microstructure in the NAB system under conditions of rapid solidification, however little data is currently available. In this paper, transmission electron microscopy is used to examine the microstructures of a series of laser surface melted NAB alloys containing from 8 to 12 wt. % Al, 3.8 to 6.5 wt. % Ni, 3.8 to 6.5 wt. % Fe, ∽1 wt. % Mn and, in some cases, lesser amounts of Ti or Zr.


2013 ◽  
Vol 683 ◽  
pp. 82-89 ◽  
Author(s):  
Borpit Thossatheppitak ◽  
Surasak Suranuntchai ◽  
Vitoon Uthaisangsuk ◽  
Anchalee Manonukul ◽  
Pinai Mungsuntisuk

Nickel Aluminum Bronze (NAB) alloys have been widely used in different kinds of machine parts where the superior resistance to corrosion and erosion in saltwater is needed. In this work, mechanical properties at high temperatures and microstructures of a NAB alloy were investigated. First, NAB specimens were prepared as an as-cast ingot and were subsequently heat-treated at 675°C for 6 hours in order to improve microstructure and mechanical properties. The mechanical properties at high temperatures in form of the plastic flow curves of the NAB alloy were characterized by a deformation dilatometer. The NAB samples were compressed at high temperature and rapidly cooled down to room temperature. The deformation temperatures of 825°C, 850°C and 900°C, a strain rate of 0.01 s-1, and a maximum compression strain of 0.4 were considered. The influences of the temperature on flow behavior of the NAB alloy were investigated. The plastic stress-strain curves at different temperatures were compared with regard to the rate of material strain hardening and softening. It was found that the compression stresses decreased with increasing temperatures. Additionally, the resulted hardness and microstructures of the alloy after forming at high temperatures were analyzed.


1999 ◽  
Author(s):  
Kenneth C. Meinert ◽  
Eric J. Whitney

Alloy Digest ◽  
2019 ◽  
Vol 68 (9) ◽  

Abstract AMS 4880-C95510 is a nickel-aluminum bronze casting useful for bushings and bearings. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on machining. Filing Code: Cu-895. Producer or source: Concast Metal Products Company.


Alloy Digest ◽  
1956 ◽  
Vol 5 (9) ◽  

Abstract AUR-O-MET 57 is a high nickel-aluminum bronze that was developed primarily for its abrasion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Cu-42. Producer or source: Aurora Metal Company.


Alloy Digest ◽  
1967 ◽  
Vol 16 (4) ◽  

Abstract PROMET-115N is a heat treatable nickel-aluminum bronze recommended for corrosion resistant, high strength bearings, gears and castings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-175. Producer or source: American Crucible Products Company.


Author(s):  
Michél Hauer ◽  
Frank Gärtner ◽  
Sebastian Krebs ◽  
Thomas Klassen ◽  
Makoto Watanabe ◽  
...  

AbstractThe present study compares prerequisites for cavitation-resistant bronzes production by different coating techniques, namely cold spraying, HVOF spraying, warm spraying and arc spraying. If optimized to maximum cavitation resistance, the deposited coatings can increase the service life of ship rudders significantly. Furthermore, these methods could enable repair processes for ship propellers. This study is meant to help selecting the right coating technology to achieve best cavitation protection for a given set of requirements. Using high-pressure warm spraying and cold spraying, properties similar to those of cast nickel aluminum bronze are achieved. Also, coatings produced by using HVOF and arc spraying have erosion rates that are only about four, respectively, three times higher as compared to cast nickel aluminum bronze, while by far outperforming bulk shipbuilding steel. Their properties should be sufficient for longer service life, i.e., less docking events for ship rudder repair. Hence, with respect to costs, HVOF and arc spraying could represent a good compromise to reach the specified coating properties needed in application, potentially even for propeller repair.


2021 ◽  
Vol 2 (1) ◽  
pp. 61-77
Author(s):  
Hamid Reza Jafari ◽  
Ali Davoodi ◽  
Saman Hosseinpour

In this work, the corrosion behavior and surface reactivity of as-cast and heat-treated nickel aluminum bronze casting alloy (UNS C95800) in 3.5 wt% NaCl solution is investigated under stagnant and flow conditions. Increasing flow rate conditions are simulated using a rotating disk electrode from 0 to 9000 revolutions per minute (rpm). Optical micrographs confirm the decrease in the phase fraction of corrosion-sensitive β phase in the microstructure of C95800 after annealing, which, in turn, enhances the corrosion resistance of the alloy. Electrochemical studies including open circuit potentiometry, potentiodynamic polarization, and electrochemical impedance spectroscopy are performed to assess the effect of flow rate and heat treatment on the corrosion of samples at 25 and 40 °C in 3.5 wt% NaCl solution. For both as-cast and heat-treated samples, increasing the flow rate (i.e., electrode rotating rate) linearly reduces the corrosion resistance, indicating that the metal dissolution rate is significantly affected by hydrodynamic flow. Increasing the solution temperature negatively impacts the corrosion behavior of the as-cast and heat-treated samples at all flow conditions.


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