Enhancement of Porosity of the Ceramic Shell in Investment Casting Process Using Needle Coke and Camphor

2014 ◽  
Vol 592-594 ◽  
pp. 269-275 ◽  
Author(s):  
Khyati Tamta ◽  
D. Benny Karunakar
Keyword(s):  
Investment Casting ◽  
Complex Geometry ◽  
Gas Permeability ◽  
Ferrous Metal ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Ceramic Shell ◽  
Needle Coke ◽  
Thin Sections ◽  
Investment Casting Process

Investment casting process has been a widely used process for centuries. It is known for its ability to produce components of complex shapes with dimensional accuracy and excellent surface finish. Investment casting has been used to make manufacture weapons, jewellery and art castings during the ancient civilization and today it is used to manufacture engineering components. In Investment casting wax patterns are made by wax injection and then coating of the wax patterns are done by ceramic slurry, made with silica flour and binder. After dewaxing and firing molten metal is poured in the shell and solidified casting can be achieved. Investment casting can be cast any ferrous and non ferrous metal which is difficult in die casting. Finishing operations are negligible and very thin sections as.75mm can also be cast which is not possible in sand casting but there are many challenges in Investment casting. It is relatively slow process because preparation of ceramic shell consumes a lot of time, permeability of shell is very low which causes gas permeability. Incorporation of chills is very difficult. Among all these challenges gas porosity is main problem because of poor permeability, entrapment of gases due to complex geometry of the shell, reuse of scrap metal. In the present work porosity of the shell can be increase by addition of mixture of Camphor and needle coke. After firing of the shell camphor and needle coke will be burnt leaving pores for the escape of entrapped gases. Mechanical properties of the both shell will be compared with each other.

Investigations for Mechanical Properties of Hybrid Investment Casting: A Case Study

2014 ◽  
Vol 808 ◽  
pp. 89-95 ◽  
Author(s):  
Parlad Kumar ◽  
Rupinder Singh ◽  
I.P.S. Ahuja
Keyword(s):  
Investment Casting ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Manufacturing Processes ◽  
Biomedical Implant ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Investment Casting Process

Conventional investment casting is one of the old manufacturing processes. It involves expensive tooling for making sacrificial wax patterns to make ceramic moulds. However, with the emergence of rapid prototyping technologies, now it is possible to make and use plastic patterns instead of wax patterns along with some advantages. In this paper, plastic patterns have been prepared by using fused deposition modeling and used for investment casting process. A case study has been discussed to make a biomedical implant by the hybridization of fused deposition modeling with investment casting. Dimensional accuracy, surface finish and hardness of the casted biomedical implants have been tested and reported.

scholarly journals Optimization of Ceramic Shells for Contact with Reactive Alloys

2008 ◽  
Vol 587-588 ◽  
pp. 157-161 ◽  
Author(s):  
Teresa P. Duarte ◽  
Rui J.L. Neto ◽  
Rui Félix ◽  
F. Jorge Lino
Keyword(s):  
Mechanical Properties ◽  
Surface Quality ◽  
Investment Casting ◽  
Chemical Reactivity ◽  
High Surface ◽  
Casting Process ◽  
Ceramic Shell ◽  
High Surface Quality ◽  
Complex Shapes ◽  
Investment Casting Process

Companies are continuously under pressure to innovate their products and processes. In Portugal, there are already several examples of enterprises that have chosen research groups, associated to universities, to straighten collaboration seeking the development of new materials and advanced technological processes, to produce components with complex shapes, high surface quality, and others, at low cost, for continuously more demanding applications. Unfortunately, these cases are still a very small number, and many efforts have to be done to enlarge the collaboration university-companies. Ti and other reactive alloys are important groups of metals that are under intense and continuous research and development. For example, the high mechanical properties, low density, osteointegration behavior, corrosion resistance to fluids and tissues of the human body, the ability to be sterilized, and the possibility to obtain complex shapes, makes Ti a very attractive material for medical applications. The investment casting process, using lost wax or lost rapid prototyping models, allows designers a great amount of freedom and capacity to quickly produce castings of high dimensional accuracy and excellent surface quality suitable for different applications. Many of the castings obtained by this process are immediately ready for use, avoiding costly machining operations and joining processes, making the process very attractive to produce precision parts in Ti and other reactive alloys. However, the high reactivity of the Ti raises several compatibility problems with the traditional materials employed on the ceramic shells for casting steels and non ferrous alloys. The fragile surface layer obtained on the interface Ti-ceramic shell, result of the Ti reaction with oxygen and nitrogen of the shell, significantly reduces the mechanical properties of the cast parts, making them useless. The aim of the present work is the study of the interface properties of the Ti-ceramic shell, in order to be able to manufacture ceramic shells of low chemical reactivity for the investment casting process of reactive alloys, namely; titanium alloys, inconel, aluminotitanates, and others. Ceramic shells manufactured with calcium and yttria stabilized zirconia and other non reactive ceramics were employed and the metallic interface characterized in terms of microscopic and microhardness properties.

Study of Shell Cracking Behavior and its Remedies in Investment Casting Process Using Quick Cast Rapid Prototype Polymer Patterns

2012 ◽  
Vol 710 ◽  
pp. 214-219
Author(s):  
Ankit Sharma ◽  
Mayukh Acharya ◽  
Alok Agarwal ◽  
Govind ◽  
S.C. Sharma ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Investment Casting ◽  
Rapid Prototype ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Cost Effective ◽  
Direct Conversion ◽  
Cracking Behavior ◽  
Engineering Changes ◽  
Investment Casting Process

Investment casting has emerged as the foremost casting process for manufacturing of intricate parts where better dimensional accuracy is required. Use of rapid prototyping polymer patterns is one of the major advancements in investment casting process. Elimination of die making step as required in the traditional wax process makes it quicker and a cost effective process. The direct conversion of 3D CAD data into rapid prototyping pattern decreases development time, chances of costly mistakes, minimizes sustaining engineering changes and extend product lifetime by adding necessary features and eliminating redundant features early in the design.

scholarly journals Caracterización morfológica y estructural del cascarón cerámico desecho del proceso de microfundición en FASAB Sogamoso (Morphological and structural characterization of ceramic shell waste in the investment casting process in FASAB Sogamoso)

2016 ◽  
Vol 16 (1) ◽  
pp. 14 ◽  
Author(s):  
Isnardo Antonio Grandas Rincón ◽  
Luis Ángel Lara González ◽  
Ricardo Alfonso Paredes Roa ◽  
Karol Lizeth Roa Bohórquez
Keyword(s):  
Structural Characterization ◽  
Investment Casting ◽  
Casting Process ◽  
Ceramic Shell ◽  
Santa Barbara ◽  
Shell Waste ◽  
Investment Casting Process

Se reportan las características estructurales y los parámetros cristalinos del material de desecho del proceso de microfundición en la Industria Militar (INDUMIL) Fábrica Santa Bárbara. Mediante la realización de pruebas normalizadas de laboratorio, tales como microscopía óptica, microscopia electrónica de barrido (MEB) y difracción de rayos X (DRX), se identifican la distribución granulométrica, la porosidad y las fracturas presentes. Además, se realiza un análisis cualitativo y cuantitativo de las fases mineralógicas, determinando la fase mayoritaria y comparándola con las fases presentes en la materia prima original. Finalmente, con base en la información obtenida, se proponen posibles usos que pueda tener el material en estudio.

Formulations, development and characterization techniques of investment casting patterns

2019 ◽  
Vol 35 (3) ◽  
pp. 335-349 ◽  
Author(s):  
Robert K. Tewo ◽  
Hilary L. Rutto ◽  
Walter Focke ◽  
Tumisang Seodigeng ◽  
Lawrence K. Koech
Keyword(s):  
Investment Casting ◽  
Manufacturing Sector ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Filler Materials ◽  
Scanning Calorimetry ◽  
Investment Casting Process ◽  
Printed Patterns

Abstract Conventionally, unfilled wax has been used as a universal pattern material for the investment casting process. With increase in demand for accurate dimensions and complex shapes, various materials have been blended with wax to develop more suitable patterns for investment casting in order to overcome performance limitations exhibited by unfilled wax. The present article initially reviews various investigations on the development of investment casting patterns by exploring pattern materials, type of waxes and their limitations, the effect of filler materials and various additives on unfilled wax, wax blends for pattern materials, plastics and polymers for pattern materials and 3D-printed patterns. The superiority of filled and polymer patterns in terms of dimensional accuracy, pattern strength, surface and flow properties over unfilled wax is also discussed. The present use of 3D patterns following their versatility in the manufacturing sector to revolutionize the investment casting process is also emphasized. Various studies on wax characterization such as physical (surface and dimensions), thermal (thermogravimetric analysis and differential scanning calorimetry), mechanical (thermomechanical analysis, tensile stress testing, dynamic mechanical analysis) and rheological (viscosity and shearing properties) are also discussed.

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