Welcome To Our Website. Any questions about PCD cutting, brazing and grinding, Call Us:+86 17700605088

Coated CBN tools for Austempered Ductile Iron cutting

2020-08-31 15:46:27

Austempered Ductile Iron (ADI) was Austempered nodular cast iron with austenite and Bainite matrix. Combining high strength bainite and spherical graphite structure. ADI has excellent comprehensive properties of high strength, wear resistance, noise absorption and vibration reduction, good notch sensitivity, high impact toughness and fatigue strength, while retaining the benefits of the original casting process, which can be made into various shape. Compared with cast steel, cast aluminum and other materials, it has the best economic performance.

 

Grade

Tensile Strength

(MPa)

Yield Strength

(MPa)

Elongation

(%)

Percussive Power

(J)

Hardness

(HRC)

1

900

650

9

100

34

2

1050

750

7

80

39

3

1200

850

4

60

47

4

1400

1100

2

35

52

5

1600

1300

1

20

56

US Standard – ASTM A897 / A897M-2015

 

After entering the 21st century, the application of ADI in automobile, construction machinery, shipbuilding heavy industry, agricultural machinery, metallurgical mining, wind power, high-speed railway accessories and other industries has developed rapidly. Such as light, medium, heavy trucks, crankshaft, camshaft, the gearbox output shaft, gear, suspension control arm, engine mounts, towing hook, suspension spring, ship’s engine cylinder liner, etc.

 the application of ADI in automobile                                          the application of ADI in automobile

Similar to ordinary ductile iron, in ADI machining process, the strength of ferroalloy matrix and nodular graphite is completely different, which is equivalent to intermittent cutting, the tool vibrates greatly, and it is easy to cause the broken edge.

 

At the same time, considering the phase diagram and process of isothermal quenching heat treatment, ADI increased austenite formation elements such as nickel (Ni 0.73wt%) and copper (Cu 0.87wt%) in the composition, as well as molybdenum elements that play the role of strengthening and oxidation resistance, and the chip adhesion tools was serious, which increased the tool’s rapid wear.

 

The cutting speed is increased from 50m/min to 200m/min. The deformation and hardening of chip play a leading role. The hardness of chip and the main cutting force are increased. As the cutting speed continues to increase, the chip gradually changes from banded to serrated shape, the chip breaking effect gradually highlights, and the cutting force gradually stabilizes. When the cutting speed exceeded 400m/min, the increase of cutting deformation and cutting temperature induced martensitic transformation of the residual austenite in ADI microstructure, and the increase of chip hardness accelerated the acceleration of PCBN blade. Continue to improve the cutting speed, chip under high temperature tissue recovery and oxidation, blade wear intensified.

For the above problems in the processing of isothermal quenching ductile iron, as far as we know that all tool enterprises are lack of effective solutions. Generally speaking, considering the discontinuous cutting edge, it is preferred to use PCBN material with medium CBN content (65%, 70%, 75% at most), and it is better to use metal binder (titanium alloy or Al/Ni/Co). At the same time, appropriate coating is also an effective means to improve the ADI processing efficiency of PCBN.

 



  • Optimizing PCD tool grinding: the transition from roughing to precision machining
    28 February 2024

    Optimizing PCD tool grinding: the transition from roughing to precision machining

    In response to the needs of end customers for grinding PCD tools, this article proposes an optimized processing plan through the analysis of customer equipment, workpieces and processing parameters. The transformation from rough machining to precision machining aims to improve processing efficiency and workpiece quality.

  • How to grind sapphire workpieces
    27 February 2024

    How to grind sapphire workpieces

    Sapphire consists of Al2O3 and has a Mohs hardness of 9, which is second only to superhard materials in hardness. Due to its superior light transmittance and wear resistance, it is mostly used in the substrate of LED light-emitting components, optical windows, and watch cases of high-end watches and cell phone cameras, etc.The processing process usually requires high precision, fast processing efficiency, low material loss and a clean working environment. Diamond is the hardest and most wear-resistant material in nature, so diamond tools are the best choice for processing sapphire materials.

  Add:  Zhongyuan Rd, Zhongyuan District, Zhengzhou, 450001, Henan, China

  Tel: +86 17700605088

  WhatsApp:+86 17700605088

  E-mail: pcd@moresuperhard.com