TPC Components AB

School of Innovation, Design and Engineering

Optimization of sprue design for advanced investment through FEA analysis

Bachelor thesis work

Basic level, 15 points

Product and Process Development

Kanthee Prathan

Mälardalens University, Academy for Innovation, Design and Engineering Supervisor, TPC AB: Daniel Kuivamäki Supervisor, university: Barrett Sauter Examinor: Janne Carlsson Presentation day: august 27th, 2020 ABSTRACT

Investment casting is a complex manufacturing method with many challenges that must be solved before components of the right quality can be produced. TPC is a company that utilizes to produce a variety of products, lately the company has higher ambition in wanting to cast higher technical demanding component like heat resistant gas turbine blades. This requires a sprue that can control the filling process, by allowing the fallen stream of molten metal to enter the moulds cavity in a laminar manner. This study has implemented the product development process by (Ulrich, 2012) to develop the requested sprue. The primary support for this study is study material given by the company also known as "PMG running spreadsheet TPC" base on theory and equations from (Jolly, 2002), which is believed to have origin in manufacturing process. The project began with recreating the textbook model after establishing a number of control parameter such as critical velocity. Then simulation software Nova flow was used to evaluate the velocity and FEM in Solidworks to study if the dimension of the model can be directly use for investment casting process. The results show that it was not possible, therefore in the concept generating phase only theory of casting was used to create new concept. Then 3 existing sprues were chosen for benchmarking to gain deeper understanding about their design intension. One of the concepts was inspired by the CEO Mark Irwin “concentric pipe design” and in total 10 concepts were created of which 6 were tested for both flow and FEM analysis. 2 concepts were chosen for further development which also became 2 final concepts, after 3 iterations of improvement. These concepts show that many improve in terms of laminar filling and higher yield than the existing benchmark sprues. Although further development is required.

The analysis shows that every step in the project has its own flaws, but that is the nature of being an engineer, as long as the problem encountered can be viewed with critical and analytical eyes. A well-considered and balanced solution can be provided, although nothing of this can be certain before a trail of test can provided to confirm any assumptions which is not included in this work.

The discussion section processes the thoughts, experience, and doubts about the project in general and the decision making leading to this report and what could have been done differently. The most significant lesson learn from this is that section is when solving a complex issue there must be very clear delimitations and well-defined goals to every specific solution. Otherwise the workload will be extensive and cause more harm than necessary.

The conclusion of this project shows that two concepts generated with the help from the product development process work better than the case study, which can be found in section 4.3, that was based on “PMG running spreadsheet TPC” calculation model, from the velocity perspective. To achieve this, the sprue uses its own geometry constrain and constricts the flow by collecting the molten metal in a “well” before the calmer stream could be distributed throughout the whole cavity. Indirectly this means that the studied material given from TPC AB could not be directly implemented into the investment production process. The given material should be seen as a complement and guidance when creating new sprues. Concerning the FEM analysis tool, it was helpful in this project in evaluating the sprues geometry expose to the assumed force in the production process to avoid unnecessary failure and therefore waste. Although if the company do not intend further work with the development of other sprues then this method is not necessary and would not have significant value to their current manufacturing process.

2 (84) ACKNOWLEGEMENT

I would like to thank everyone, friends and family who supported me in this project during this last few month and who showed great understanding for my absence from all the important events. Many thanks and appreciation to my supervisor(s) in helping me to understand the many issues in this work so that appropriate solutions could be provided. Also, great thanks to TPC AB, especially Mark Irwin for giving me the opportunity to conduct this study and to learn so much about their process and the casting industry. This have been a great lesson-learn journey without them this would not have been possible.

Special thanks to my better half who has been supportive in both time and effort by reading this report countless times and correcting my mistakes. Without her this study would not have been possible.

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CONTENTS

1. INTRODUCTION ...... 10 1.1. BACKGROUND ...... 10 1.2. PROBLEM FORMULATION ...... 10 1.3. PURPOSE AND RESEARCH QUESTIONS...... 12 1.4. DELIMITATION ...... 12 2. METHODOLOGY ...... 13 2.1. PRODUCT DEVELOPMENT PROCESS ...... 13 2.1.1. PLANNING ...... 13 2.1.2. CONCEPT DEVELOPMENT ...... 13 2.2. INFORMATION GATHERING...... 15 2.2.1. LITERATURE STUDY ...... 15 2.2.2. OBSERVATION ...... 15 2.2.3. CONFERENCE CALL ...... 16 2.2.4. DISCUSSION ...... 16 2.2.5. CASE STUDY ...... 16 2.2.6. BENCHMARK ...... 16 2.2.7. FEM ANALYSIS ...... 17 2.2.8. SOFTWARE ...... 17 2.3. 3D-PRINTING ...... 17 3. THEORETICAL FRAMEWORK ...... 18 3.1. WHAT IS CASTING? ...... 18 3.2. INVESTMENT CASTING ...... 18 3.3. SAND CASTING ...... 19 3.4. CASTING RULES ...... 20 3.5. GATING SYSTEM ...... 21 3.6. LAMINAR FLOW ...... 22 3.7. COMPANY ANALYSIS ...... 23 3.7.1. THE CASTING PROCESSES ...... 24 3.7.2. CONCENTRIC PIPE DESIGN ...... 24 4. EMPIRICS ...... 25 4.1. OBSERVATION ...... 25 4.1.1. COMPANY PRODUCTION PROCESS ...... 25 4.1.2. DISCUSSION ...... 27 4.1.3. CONFERENCE CALL ...... 27 4.2. DESIGN STRATEGY ...... 27 4.3. CASE STUDY ...... 30 4.4. BENCHMARK ...... 33 4.5. CONCEPTS DEVELOPMENT ...... 37 4.5.1. IDENTIFY THE CUSTOMERS NEED ...... 38 4.5.2. ESTABLISHED TARGET SPECIFICATIONS ...... 38 4.5.3. CONCEPT GENERATING ...... 38 4.5.4. CONCEPT SELECTION ...... 55 4.5.5. TEST PRODUCT CONCEPTS ...... 55 5. RESULTS ...... 71 5.1. CONCEPT4.3 ...... 71 5.2. CONCEPT6.2 ...... 72 6. ANALYSIS ...... 74 6.1. DESIGN STRATEGY ...... 74 6.2. CASE STUDY ...... 74 6.3. BENCHMARK ...... 74 6.4. TESTING OF THE CONCEPT ...... 75

4 (84) 6.5. RESULTS ...... 77 6.6. RESEARCH QUESTIONS ...... 78 7. DISCUSSION ...... 80 8. CONCLUSION ...... 81 9. RECOMMENDATION ...... 81 10. REFERENCES ...... 82 11. APPENDIX ...... 83

5 (84) List of Figure

Figure 1, Product development process...... 13 Figure 2, the frontprocess and what activity this process includes...... 14 Figure 3, the phenomena of vena contracta in (a) and how the flow behave if the down sprue are cynlindrical in (b) and the shaping of the downsprue to utilize the natural shape in (c) (Jolly, 2002)...... 22 Figure 4, the actual casting process...... 24 Figure 5, the observation of the actual investment casting process at the company...... 25 Figure 6, test piece, the left figure is without and on the right with the standard ingate...... 28 Figure 7,the two halves of a sand casting mould...... 30 Figure 8, the results from the flow simulation, shows the filling sequence of 10% - 90%...... 31 Figure 9, FEA analysis used to evaluate the dimension...... 31 Figure 10, benchmark sprue no.1, the left side is the actual footage and the right is a recreated 3d-model...... 33 Figure 11, benchmark sprue no.2, the left side is the actual footage and the right is a recreated 3d-model...... 34 Figure 12, benchmark sprue no.3, the left side is the actual footage, the middle sprue is the original design and the right is a recreated 3d-model...... 35 Figure 13, how mounting can be solved in a one level solution...... 37 Figure 14, concept A...... 40 Figure 15, concept B...... 41 Figure 16, concept C...... 42 Figure 17, concept D...... 43 Figure 18, concept E...... 44 Figure 19, concept F...... 45 Figure 20, concept G...... 46 Figure 21, concept H...... 47 Figure 22, concept I...... 48 Figure 23, concept J...... 49 Figure 24, concept4.1...... 50 Figure 25, concept6.1 shows the same runner design as concept4.1 in the right figure...... 51 Figure 26, concept4.2...... 52 Figure 27, concept4.3, where runners are being redesign, angle lowered, and the "skirt" are being introduce to this version ...... 53 Figure 28, final concept6.3 ...... 54 Figure 29, concept1 flow simulation...... 57 Figure 30, FEA simulation of concept1...... 58 Figure 31, concept2 flow simulation...... 58 Figure 32, FEA simulation of concept2...... 59 Figure 33, concept3 flow simulation...... 59 Figure 34, FEA simulation of concept3...... 60 Figure 35, concept4 flow simulation...... 61 Figure 36, FEA simulation of concept4...... 62 Figure 37, concept5 flow simulation...... 62 Figure 38, FEA simulation of concept5...... 63 Figure 39, concept6 flow simulation...... 64 Figure 40, FEA simulation of concept6...... 64 Figure 41, concept4.2 flow simulation...... 65

6 (84) Figure 42, FEA simulation of concept4.2...... 66 Figure 43, concept6.1 flow simulation...... 66 Figure 44, FEA simulation of concept6.1...... 67 Figure 45, flow simulation of concept4.3...... 68 Figure 46, FEA simulation of concept4.3...... 68 Figure 47, flow simulation of concept6.2...... 69 Figure 48, FEA simulation of concept6.2...... 70 Figure 49, concept4.3 the left picture shows the isometric view and the right view is cross sectional view ...... 71 Figure 50, the left picture shows concept4.3 from top view and right picture shows the sprue from below ...... 72 Figure 51, concept6.2 the right picture shows the isometric view and the right is a cross.sectional view ...... 73 Figure 52, concept6.2 the left picture shows concept6.2 the sprue from above and the right shows the sprue from below...... 73

7 (84) List of tables

Table 1, parameters on the standardized testing piece...... 29 Table 2. properties of benchmark sprue no. 1...... 34 Table 3, properties of benchmark sprue no. 2...... 35 Table 4, properties of benchmark sprue no. 3...... 36 Table 5, findings from analysing the chosen sprues...... 36 Table 6, the identify needs from the company...... 38 Table 7, the established target specifications...... 38 Table 8, properties of concept A...... 40 Table 9, properties of concept B...... 41 Table 10, properties of concept C...... 42 Table 11, properties of concept D...... 43 Table 12, properties of concept E...... 44 Table 13, properties of concept F...... 45 Table 14, properties of concept G...... 46 Table 15, properties of concept H...... 47 Table 16, properties of concept I...... 48 Table 17, properties of concept J...... 49 Table 18, properties of concept4.1 ...... 50 Table 19, properties of concept6.1...... 51 Table 20, properties of concept4.2...... 52 Table 21, properties of final concept4.3...... 53 Table 22, propertis of final concept6.3...... 54 Table 23, the scoring matrix...... 55 Table 24, material propertys data...... 56 Table 25, the comparing results of concept4.3 against benchmark sprues ...... 72 Table 26, comparing results between concept 6.2 against benchmark sprues...... 74

8 (84) Abbreviation

FEM Finite Element Method

FEA Finite Element Analysis

CAD Computer Aided Design

9 (84) 1. INTRODUCTION

The process of casting can be dated to a prehistoric time and has been developed ever since. What was known as lost-wax process is today Investment casting. Investment casting is responsible for the production of most of today’s com