scholarly journals Aqueous electrophoretic deposition as a method for producing an investment casting shell mould ceramic face-coat. Part 1: formation of a carbon-filled investment casting wax electrode material

2013 ◽  
Vol 48 (21) ◽  
pp. 7476-7492 ◽  
Author(s):  
P. J. Roach ◽  
C. B. Ponton
Keyword(s):  
Electrophoretic Deposition ◽  
Investment Casting ◽  
Electrode Material ◽  
Shell Mould ◽  
Face Coat

Interactions between TiAl and ZrO2 Face Coat during Centrifugal Investment Casting

2014 ◽  
Vol 1044-1045 ◽  
pp. 59-62
Author(s):  
Yan Fei Chen ◽  
Yuong Chen ◽  
Jiang Ping Tu ◽  
Shun Qi Zheng
Keyword(s):  
Investment Casting ◽  
Ceramic Shell ◽  
Tial Alloys ◽  
Good Oxidation Resistance ◽  
Specific Strength ◽  
High Specific Strength ◽  
The Face ◽  
Shell Mould ◽  
Near Net Shape ◽  
Face Coat

γ-TiAl alloys are emerging as potential light-weight, high-temperature structural materials and possess wide capacities of engineering applications in aeronautics, space and automobile industries because of their low density, high specific strength and specific modulus, good oxidation-resistance and creep-resistance. Investment casting is introduced to complex TiAl net-shape or near net-shape components. In this research, ZrO2 (CaO stabilized) was chosen as the face coat materials for the investment casting of TiAl alloys. The present study mainly focuses on the fabrication of ceramic shell mould for TiAl investment casting. Optimisation of reducing the stress in cast-mould system was carried out. The processing technology of the invented ceramic shell moulds was successfully verified in the investment casting of prototype TiAl parts. The interfacial reaction between TiAl alloys and ZrO2 ceramic mould was analyzed using OM, SEM, EDS and XRD. The experimental results showed that, when the rotation speed is 200 rpm and 400 rpm, the thickness of reaction layer is about 5μm and 20μm, respectively.

Solidification and Interface Reaction of Titanium Alloys in the BaZrO3 Shell-Mould

2015 ◽  
Vol 828-829 ◽  
pp. 106-111 ◽  
Author(s):  
Chong He Li ◽  
Jin He ◽  
Chao Wei ◽  
Hong Bin Wang ◽  
Xiong Gang Lu
Keyword(s):  
Titanium Alloy ◽  
Investment Casting ◽  
Interface Reaction ◽  
Base Material ◽  
Tini Alloy ◽  
The Novel ◽  
Coarse Powder ◽  
Elemental Diffusion ◽  
Shell Mould ◽  
Mould Base

The investment casting technology is one of the major methods to produce the parts of the titanium due to its low production cost. However, the high activity of titanium melt gives rise to the requirement of high chemical stability of shell materials, to avoid or decrease the interfacial reaction between the mould and the melt. In this paper, a novel BaZrO3 – coated Al2O3 shell was first introduced to the investment casting of titanium alloy. The grain size and baking temperature on the properties of the novel mould were investigated, and then the Ti6Al4V and TiNi alloys were successfully casted by means of this shell. The alloy-mould interaction was discussed. The results showed that the mould achieve high mechanical properties when the content of coarse powder was 50% after sintering 4 hours under 1500°C, and the BaZrO3 coating exhibited an effective barrier to avoid the direct contact between the mould base material and the melt, the thickness of reaction layer of TiNi alloy was about 8 μm, and 17 μm to Ti6Al4V alloy, no refractory particles and elemental diffusion were observed inside the metal. This may imply that BaZrO3 is a promising candidate material for the investment casting of titanium alloy.

Differential Ceramic Shell Thickness Evaluation for Direct Rapid Investment Casting

2013 ◽  
Vol 315 ◽  
pp. 418-422 ◽  
Author(s):  
M.F.M. Omar ◽  
S. Sharif ◽  
Mustaffa Ibrahim ◽  
Mohd Hasbullah Idris ◽  
A.S.A. Fadzil ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Investment Casting ◽  
High Speed ◽  
Shell Thickness ◽  
Direct Method ◽  
Low Cost ◽  
Acrylonitrile Butadiene Styrene ◽  
Rp Process ◽  
Shell Mould ◽  
Crack Defect

Rapid prototyping (RP) process offers a promising economical way as a sacrificial pattern in investment casting (IC) at high speed and low cost for low volume part manufacturing. However direct sacrificial RP pattern have encountered shell cracking during burnout process due to polymer based materials. Shell mould thickness was need to be concerned to have strong enough to withstand RP part expansion for employing direct method. The aim of present research was to compare the efficacy of different shell thickness for aluminum casting part fabricated from acrylonitrile butadiene styrene (ABS) and acrylate based material made from FDM and MJM respectively. The hollow RP pattern has been used directly to produce ceramic moulds. The feasibility of ceramic mould has been assessed in term of burnout ability and crack defect. Dimensional accuracies and surface roughness of the castings part have been observed in this investigation. Result shows thicker mould with proposed stuco procedure resulted without any crack defect for botRP part and no residual ash remained when firing higher than 870°C of temperature.In addition, FDM produced better accuracy for overall mould thickness, but MJM have better surface roughness. Therefore both direct RP pattern were suitable to be used in IC process with proposed shell thickness.

Toughening of Ceramic Shell Mould with Rice Husk Fiber (CSm-RH) to Improve Strength Property and Mould Performance

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Noor Hasliza Kamarudin ◽  
◽  
Zawati Harun ◽  
Rosniza Hussain ◽  
Mohd Riduan Jamalludin ◽  
...  
Keyword(s):  
Rice Husk ◽  
Investment Casting ◽  
Ceramic Body ◽  
Ceramic Shell ◽  
Adhesion Properties ◽  
Ceramic Structure ◽  
Green Strength ◽  
Body Strength ◽  
Shell Mould ◽  
Casting Industry

For ages, ceramic shell mould (CSm) have been extensively applied in investment casting industry. The formation of CSm requires multiple steps of dipping, layering drying and firing stages. The later steps are very crucial as the solidification thin layer CSm that consist of loose ceramic particles easily cracks when exposed to the higher thermal effect. The inclusion of fiber or any reinforces phases is able to enhance fired ceramic body and also strengthen the green ceramic structure. Thus, the feasibility of rougher NaOH treated rice husk fiber (RHT) prior embedded into composited structure has shown a significant CSm improvement by induced a better adhesion properties and larger bonding area with brittle ceramic matrix, resulted in increased green strength (1.34 MPa) and fired body strength (4.32 MPa). Owing to the decomposed of lignin layer in CSm with untreated rice husk fiber (CSm-RHU) exhibited a higher porosity that provide a better permeation paths of air flow during molten metal pouring as increased 30 % from the standard CSm permeability, giving an enormous benefit for investment casting cooling process. Overall, the incorporation of RHT fiber in a CSm matrix of both green and fired body governed in toughening of brittle ceramic body, hence avoid failure to the casting mould.

The Study of the Oxidation of a Ti–45Al–2Nb–2Mn–0.2B Alloy in the Investment Casting Using an Yttria Face Coat Mould

2013 ◽  
Vol 81 (1-2) ◽  
pp. 287-298 ◽  
Author(s):  
X. Cheng ◽  
C. Yuan ◽  
N. R. Green ◽  
P. A. Withey
Keyword(s):  
Investment Casting ◽  
Face Coat

Permeable Rice Husk Fibre Shell Mould System

2013 ◽  
Vol 372 ◽  
pp. 331-335 ◽  
Author(s):  
Zawati Harun ◽  
Noor Hasliza Kamarudin ◽  
Muhamad Zaini Yunos
Keyword(s):  
Rice Husk ◽  
Investment Casting ◽  
Open Porosity ◽  
Casting Process ◽  
Casting Defects ◽  
Ceramic Shell ◽  
Volatile Elements ◽  
Shell System ◽  
Mould Filling ◽  
Shell Mould

Basically, permeability of ceramic shell mould system play an important role in minimizing the casting defects in most investment casting shell. The mould has to be sufficiently permeable to obtain complete mould filling during casting process. Mould fill can be improved by increasing the open porosity that definitely will increase permeability ceramic shell mould. The elimination of rice husk volatile elements has contributed to the increment of pore structure that provides a great deal of connected pathways through the ceramic shell which directly will increase the permeability of the ceramic shell mould during casting process. Indeed, the rice husk fibers additions increase the permeability after firing by a factor 3 compared to the standard shell mould system (without fiber) that makes its an excellent alternative in producing higher permeable ceramic shell system.

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