Daido Steel Co., Ltd. · TSE:5471
Daido Steel — Technical Presentation (October 2021)
25 slides from Daido Steel's technical presentation, Oct 4, 2021
Slide 1: H13 Modified High Thermal Conductivity Powder for 3D Printing
1 October 4, 2021 H13 Modified High Thermal Conductivity Powder for 3D Printing Takashi Yoshimoto Paul W. Britton Koichiro Inoue Naoki Yokoi Hiroyuki Ohisa
Slide 2: Contents
2 Contents 1. Introduction 2. Concept of New AM powder ・High thermal conductivity ・Less cracking during building 3. Mechanical Properties 4. Practical Evaluation
Slide 3: Material Development in Daido
3 Material Development in Daido Advanced die casting die steels Alloy powders and AM techniques High hardenability and toughness steel NADCA Grade F & NADCA Grade C (Presented in NADCA 2013) NADCA Grade F NADCA Grade C DAPTM(Daido Alloy Powder)
Slide 4: Introduction
4 Introduction Die steel with high thermal conductivity contributes to faster cooling in die casting dies. Surface temperature of sprue core Lower die temperature Shorter cycle time Less thermal damage Steel A H13 Steel A;1.6 times higher thermal conductivity than H13.
Slide 5: Introduction
5 Introduction Die steel with high thermal conductivity contributes also to improve a product quality. Cross sectional Movable die Cross section microstructure of the cast products Cast product of the biscuit surface Steel A 35~37 W/(m・K) Die H13 24~27 W/(m・K) Biscuit Sprue core Die After 5,000 shot
Slide 6: Additive Manufacturing of Dies
6 Additive Manufacturing of Dies Conformal cooling channels made by additive mfg. is now available to enhance the internal cooling. Linear Conformal The inserts of die casting dies made by the SLM cooling channel cooling channel https://www.additivemanufacturing.media/articles/in-automotive-is- http
Slide 7: Conventional Powder for AM
7 Conventional Powder for AM H13 and 18%Ni Maraging steel powders are mainly used, but each has its own problems. Cracking during Thermal Mechanical Steel grade build Conductivity Properties 18%Ni Great Low Good maraging steel No cracking 17 W/(m・K) Bad High H13 / H11 Good Easy to crack 24 W/(m・K) H
Slide 8: Concept of Powder Development
8 Concept of Powder Development High crack resistance during build and high thermal conductivity. Maraging Target Crack resistance Steel Product during build H13 Thermal conductivity
Slide 9: New Powder Material DAP-AM HTC
TM 9 New Powder Material DAP -AM HTC Daido Alloy Powder – for Additive Manufacturing High Thermal Conductivity Cracking during Thermal Mechanical Steel grade build Conductivity Properties 18%Ni Great Low Good Maraging steel No cracking 17 W/(m・K) Bad High H13 / H11 Good Easy to crack 24 W/(m・K) Good
Slide 10: Thermal Conductivity
10 Thermal Conductivity The built specimens with HTC powder has high thermal conductivity. Because HTC is lower Silicon content than H13. Effects of Si content on thermal conductivity of die steel 0.4%C-steels
Slide 11: Formability / Cracking during Build
11 Formability / Cracking during Build Cracking was suppressed due to the reduction of hardness during build. 0.23%C 0.37%C HTC45 / 48 HRC H13 / 54 HRC Notched Specimen No crack Gross crack 80 30 90° Build 10.0 Direction 2.5 Built with preheating at 200 oC
Slide 12: Alloy Design of Modified Powder
12 Alloy Design of Modified Powder Our new powder grades HTC40 and HTC45 are alloy-designed based of H13. Composition (mass%) Hardness C Si Mn Ni Cr Mo V Co Applications HRC Thin tools HTC45 Steel A 0.23 0.1 0.4 - 5.3 1.2 0.4 - 45-50 e.g. Core pins Thicker tools Steel B HTC40 0.13 0.1 0.4 - 5.3 1.2
Slide 13: Flow & Density
13 Flow & Density HTC powders have good flow, which makes it possible to form dense parts. Selective Laser Melting(SLM) process requires powder flow-rate to achieve high density. Building Condition Good flow Laser Power 300 W Scan Speed 600 mm/s Hatching Distance 0.13 mm Laser Spot Diameter 180 μm L
Slide 14: Mechanical properties evaluation
14 Mechanical properties evaluation Built specimens with HTC powder ◇ Heat treatment / Hardness HTC / SLM ◇ Nitriding hardness Atomized Built Heat treated Conventionally cast and forged H13 ◇ Impact Toughness H13 / Forged Cast Forged Heat treated ◇ Tensile Strength, Elongation
Slide 15: Heat treatment / Hardness
15 Heat treatment / Hardness The hardness of HTC can be adjusted by tempering as same as the forged H13. Building Shot Blasting Base Plate Effective in preventing crack during tempering Tempering Cutting off 550~650℃ Heat treatment for HTC requires only tempering.
Slide 16: Nitriding hardness
16 Nitriding hardness The nitriding hardness of the HTC is same as one of the forged H13. Hardness distribution after gas nitriding H13 /Forged HTC45 H13 HTC45 /SLM Resin SLM Forged Maximum Hardness 1103 1106 /HV Initial Hardness 450 440 /HV
Slide 17: Impact Toughness
17 Impact Toughness The impact toughness of the HTC is higher than that of the forged H13. H13 /Forged HTC45 /SLM [J/cm2] HTC40 /SLM Build direction Size of built samples：15×60×15 mm Heat treatment Condition HTC45：Tempered to 45~50HRC HTC40：As-built(43HRC) Tempered to 44HRC
Slide 18: Tensile Strength, Elongation
18 Tensile Strength, Elongation The tensile strength and ductility of the HTC is comparable to forged H13. H13 /Forged HTC45 /SLM HTC40 /SLM Size of built samples：15×100×15 mm Heat treatment Condition Build direction HTC45 ：Tempered to 45~50HRC HTC40 ：As-built(43HRC) Tempered to 44HRC
Slide 19: Practical evaluation
19 Practical evaluation ◇ Heat checking resistance ◇ Building mock-up dies
Slide 20: Heat checking Resistance
20 Heat checking Resistance HTC45 has better heat checking resistance than forged H13. Forged H13(47.6HRC) HTC45(48.9HRC) Appearance 580oC after test at center of the 0.88mm Crack depth 1.84mm specimen 4,000 cycles R6, 1 mm Notched Heat checking test procedures
Slide 21: How thermal conductivity affects heat checking resistance
21 How thermal conductivity affects heat checking resistance Thermal stress applied on surface σ=CxExαx⊿T C=f(ν) ν: Poisson’s ratio Almost same in forged H13 E: Young’s modulus and SLM built HTC45 α: Thermal expansion coefficient ∆T: Temperature difference between the surface and inside ∆T=f(λ) λ: T
Slide 22: Building mock-up dies
22 Building mock-up dies Core Insert Model of HTC40 Insert Model of HTC45 Φ100 60 80 3D-CAD 50 160 Cooling Channel Unit : mm Φ5.0 35 45 160
Slide 23: New Powder Material DAP-AM HTC
TM 23 New Powder Material DAP -AM HTC The developed powders are suitable for additive manufacturing and are sufficiently durable as a die-casting dies after build. Cracking during Thermal Mechanical Steel grade build Conductivity Properties 18%Ni Great Low Good Maraging steel No cracking 17 W/(m・K)
Slide 24: Thank you for your attention
24 Thank you for your attention. Please vｉｓｉｔ us at booth 817 International Mold Steel
Slide 25: NADCA publication and copyright notice
The presentation titled "H13 Modified High Thermal Conductivity Powder for 3D Printing" was published as transaction T21-052, as part of the North American Die Casting Association's (NADCA) 2021 Die Casting Congress. Copyright of the presentation is held by NADCA. This presentation should not be rep