Investment casting processes, Steps and Applications by polayya chintada

Investment casting processes, Steps and Applications by polayya chintada

1. P roduction Technology: investment casting COURSE CODE: C211 REGULATION: R19 2 nd BTECH 2 nd SEM PREPARED BY : POLAYYA CHINTADA M.TECH,M.B.A,(PhD) ASSISTANT PROFESSOR LENDI INSTITUTE OF ENGINEERING AND TECHNOLOGY

2. 2 PRODUCTION TECHNOLOGY SYLLABUS UNIT 1: Introduction: Importance and selection of manufacturing processes. Casting Processes : Introduction to casting process, process steps; pattern: types, materials and allowance; Cores: Types of cores, core prints, principles and design of gating system; Solidification of casting: Concept, solidification of pure metal and alloy; Special casting processes: Shell casting, investment casting, die casting, centrifugal casting, casting defects and remedies. provide insight into Working principles of different metal casting processes and gating system COURSE OBJECTIVE: COURSE OUTCOMES: Explain different metal casting processes and gating systems. (L2) APPLICATIONS: Identify different patterns and their allowances (L3) 1 . Heavy Equipment : Construction, farming and mining 2. Defence : Vehicles, artillery, munitions, storage and supporting equipment 3. Hardware : Plumbing industry pipes, joints, valves and fitting Identify the various casting defects. (L3 )

3. Introduction to investment casting Commonly referred to as “Lost wax Casting”. The Pattern is made up of wax or plastic Such as Polystyrene because of low melting temperature. The molten metal is poured into the ceramic mold and mold is formed using wax pattern.(The wax assembly is dipped into high-grade ceramic slurry ) Investment casting is often referred to as "lost-wax casting" because the wax pattern is melted out of the mold after it has been formed. Investment casting can make use of most metals, most commonly using Al alloys, bronze alloys, Mg alloys, cast iron, stainless steel, and tool steel. Parts that are typically made by investment casting include those with complex geometry such as turbine blades or firearm components.

4. S teps in investment casting

5. P r oc es s o f I nv e s tm e n t C as t i n g 1. Pattern Making: Manufacture Wax Pattern Master Die desired Allowances(Wax ,Ceramic Coating and Metal shrikange) added into Master Die Fig. 1 Wax Injection

6. 2 . A sse m b l y Several Wax Pattern Combine for a Single Casting Wax Bar( Central Sprue) Pouring Cup Wax pattern Tree Fig. 2. Assembly

7. 3 . S h el l B u l i d i n g Dip Assembly in a Refractory Slurry Refractory Slurry(Fine Grained Silica,Water and Binders) Achieve Required Ceramic Coating Fig. 3. Shell Building

8. 4 . De w a x Allow to Harden in air Ceramic Mold is turned upside down and heated(90-175 ‘C) Wax flow out of Mold Fig. 4. Dewax

9. 5 . M e t a l C as t i n g P o u r i n g Ceramic mold further heated(550-1100 ‘C) To eliminate any left over wax, contaminants and drive water out Metal Casting poured while mold still hot Fig. 5. Metal Casting Pouring

10. 6 . K n oc k o u t a n d C u t Of f Once the casting has cooled sufficiently, the mold shell is chipped away from the casting Gates and Runners are cut from the casting Fig. 6. Knockout Fig. 7. Cut Off

11. A e r o spac e I n d u s t r y Turbine airfoils Aircraft engine Industrial gas turbine industries

12. Med i ca l I ns t r u m e n t s Surgical implants e.g. knee & hip joints Ti 6 Al 4 V alloys, Co-Cr-Mo alloys

13. M i l i t a r y E q u i p m en t Military equipment need to meet very tight tolerances and high quality standards Joysticks for drone planes/UAVs Gun triggers, hammers & sights Trigger guards Bolt catches Bolt carriers

14. 3 D P r i n t i n g Paving way for new opportunities .. Process of making a three-dimensional solid object of virtually any shape from a digital model

15. Y ours : POLAYYA CHINTADA M.TECH,M.B.A,(PhD) ASSISTANT PROFESSOR