The document summarizes research on using laser cladding to produce an in-situ TiC-Fe composite coating on mild steel. Key findings include: 1) High quality coatings with complete metallurgical bonding between the clad and substrate were produced without porosity or cracks by optimizing laser processing parameters like power, scan speed, and powder feed rate. 2) The microstructure and TiC morphology within the clad layer could be controlled by varying the processing conditions. 3) Future work is proposed to further optimize the process parameters, coating compositions, and investigate the relationship between microstructure and wear resistance properties.

1. In-Situ TiC-Fe Deposition on Mild Steel Using Laser Cladding Process Ali Emamian Department of Mechanical and Mechatronics Engineering November 18, 2009

2. Contents Introduction Motivation Objectives Experimental Approach and Procedure Results and Discussion Summary Future Work

3. Matrix Hard particles Introduction Hard facing Methods Coating Heat Treatment Carburizing Composite coating Metal matrix Bronizing Ceramic coating

4. Laser cladding is a method that can be used to form metal matrix composite Creates a small heat affected zone Melts the powder and substrate Mixture of powder can be pre-place (pre-place method) or fed by nozzle into the melt pool (dynamic blow method) Introduction

5. Laser cladding (dynamic blow) D P D L Introduction

6. Introduction Laser Cladding to produce composite coating In-Situ Process Direct Adding carbide (ex-situ)

7. What is “in-situ” laser cladding ? Heating combined pure powders under a laser heat source generates chemical reaction which produces the desired metal matrix of ceramic reinforcement; Fe+Ti+C Fe + TiC c Fe Ti Matrix (Fe) TiC Introduction

8. In-situ process advantages Particles are thermodynamically stable in the metal matrix Reinforcing’ size can be controlled Rapid solidification can produce finely dispersed ceramic particles High metal/ceramic bond strength (i.e. matrix can transfer the applied stress, easily) Introduction

9. Why TiC? TiC has : High melting point (3067 º C) High Young Modules High specific strength High hardness (3000 HVN) 30% greater than WC Low density (WC is almost 3 times heavier) Introduction

10. Literature review (ex-situ) Ariely, Laser surface alloying of steel with TiC (1991). Tassin, Carbide-reinforced coatings on AISI 316 L stainless steel by laser surface alloying (1995). Axén, Abrasive wear of TiC-steel composite clad layers on tool steel (1992). Jiang, Laser deposited TiC/H13 tool steel composite coatings and their erosion resistance (2007). Li, Micro structural characterization of laser-clad TiCp-reinforced Ni-Cr-B-Si-C composite coatings on steel (1999). Wanliang, Microstructure of TiC dendrites reinforced titanium matrix composite layer by laser cladding (2003). Hidouci, Microstructural and mechanical characteristics of laser coatings (2000). Wu, Microstructure and mechanical properties at TiCp/Ni-alloy interfaces in laser-synthesized coatings (2001). Literature review

11. Literature review (In-situ) Cui, In situ TiC particles reinforced grey cast iron composite fabricated by laser cladding of Ni–Ti–C system (2007). Wang, Microstructure and wear properties of TiC/FeCrBSi surface composite coating prepared by laser cladding (2008). Yang, In-situ TiC reinforced composite coating produced by powder feeding laser cladding (2006). Yan, In situ laser surface coating of TiC metal-matrix composite layer (1996). Yang, S. Fabrication of in-situ synthesized TiC particles reinforced composite coating by powder feeding laser cladding (2005). Wu, X. In situ formation by laser cladding of a TiC composite coating with a gradient distribution (1999). Yang1, In-situ TiC reinforced composite coating produced by powder feeding laser cladding (2006). Wang, In situ synthesized TiC particles reinforced Fe based composite coating produced by laser cladding (2009). Literature review

12. Have mostly focused on pre-place method Mainly used Ni or Co alloys as a binder Did not explain TiC formation mechanism Did not investigate the relationship between clad microstructure and laser processing condition Produced carbides which are combination of Ni, Fe, Co, Cr, B or Si. Variety of carbides other than TiC are produced in a complex solidification process Motivation Motivation

13. Objective To form in-situ TiC in Fe matrix To form high quality clad (complete metallurgical bonding between clad and substrate without porosity and crack) Substrate Clad

14. Milestones To fully understand the effects of processing parameters on clad characteristics To determine the Fe-TiC clad microstructure from laser processing parameters To determine an optimum cladding condition to produce a high performance Fe-TiC To evaluate hardness and wear resistance in relation to the clad processing condition Objectives

15. Experimental set up Chemical composition of powder: 24.9 wt% Ti, 5.1 wt% C, 70 wt% Fe Powders’ size: maximum 0.04 mm Laser: Fiber Laser (1.1kW) iPG Diameter of laser beam: fixed at 2.5 mm Deposition method: Dynamic Blow Substrate: AISI 1030 (Carbon Steel) Experimental approach

16. Ti/C ratio Experimental approach

17. No bond or clad Clad-No bond Clad with partial bond High quality Clad Results and discussion Table of Results No Power W Scan speed mm/s Feed rate g/min 1 250 2 8 2 250 4 8 3 250 6 8 4 400 2 8 5 400 4 8 6 400 6 8 7 650 2 8 8 650 4 8 9 650 6 8 10 650 8 8 11 650 10 8 12 650 12 8 13 650 16 8 No Power W Scan speed mm/s Feed rate g/min 14 700 6 8 15 700 6 4 16 800 6 8 17 800 6 4 18 800 2 8 19 800 3 8 20 800 4 4 21 900 6 8 22 900 8 8 23 900 6 4 24 900 8 4 25 900 4 4 26 1000 4 4

18. Results and discussion

19. High quality limit

20. Un-bonded clad microstructure Fe Matrix TiC Cross section Results and discussion

21. Un-bonded clad Results and discussion Region Ti conc. (wt%) Fe conc. (wt%) Dark grey particles 95.2 4.8 Region 1 8.7 91.3 Region 2 16.5 83.5

22. Bonded clad Microstructure Fe Matrix TiC Results and discussion

23. Bonded clad Graphite C TiC Longitudinal section Results and discussion

24. Results and discussion

25. Clad Substrate Results and discussion

26. Increasing the scan speed 2 mm/sec 12 mm/sec 10 mm/sec 8 mm/sec 6 mm/sec 4 mm/sec Clad Bottom Clad Bottom Clad Bottom Clad Bottom Clad Bottom Clad Bottom Laser power 900 Powder feed rate 4g/min Results and discussion

27. 2 mm/sec Increasing the scan speed Clad Top 4 mm/sec 6 mm/sec 8 mm/sec 12 mm/sec 10 mm/sec Clad Top Clad Top Clad Top Clad Top Clad Top Results and discussion Laser power 900 Powder feed rate 4g/min

28. Ternary phase diagram 2200C 2400C Results and discussion

29. TiC formation Fe powders melt Ti and C dissolve in Fe Ti and C react to form TiC layer Results and discussion TiC C Material Fe Ti C Melting point °C 1538 1668 3400

30. Fe Ti C C Ti Increasing the temperature TiC Results and discussion

31. Summary In-Situ TiC has been formed during the laser cladding process It was shown that TiC morphology can be controlled by effective energy and powder deposition density A map to predict the clad quality based on process parameters has been developed

32. Future work Complete understanding of in-situ Fe-TiC coating , laser process parameters, microstructure and surface properties relationship Process Control Optimization the powder composition Investigation of wear resistance behaviour Future work

33. Future work Process control TiC morphology and microstructure Wear behaviour study Future work

34. Process control High quality bonding and clad area Different microstructure and TiC morphology Different scan speed 1 2 3 4 Future work

35. Wear investigation 1 2 3 4 n Wear test machine Investigation of surface, wear modes Future work Comparison of wear behaviour of different TiC morphology Process control

36. Powder composition optimization Now 70%Fe Ti- 45 %at C Future work 70%Fe Ti- 50 % at C Future work 70%Fe Ti- 55 % at C Graphite formation (self lubrication ) Ti+ C = TiC Future work

37. Fe Ti C 70%Fe Ti-55%C Ti-50%C Ti-45%C

38. Fe percentage decreasing Ti Fe C 70 60 50% Fe 50%C 55%C Optimize the Ti:C ratio Fe+C+TiC

39. Future work Process optimization Microstructure characterization Wear behaviour investigation Future work

40. Time table Future work Activity Winter 2010 Spring 2010 Fall 2010 Winter 2011 Spring 2011 Fall 2011 Winter 2012 Investigation on optimum process parameters Investigation on optimum compositions TiC phase formation and morphology analyses Wear resistance investigation and analysis-Process modification Thesis writing Defence

41. Thanks

44. Y=ax+b

45. 1400 C

46. Y=ax+b

47. 1000 C

55. Laser Power Increasing

56. In situ formation by laser beam Methods: Pre place Dynamic blowing

57. Future work Fe( γ )+ G+TiC