Dry sliding friction wear behaviour of high power diode laser hardened steels and cast iron

Abstract

High power diode laser hardening of steels, namely AISI 1018l AISI 4140 and grey cast iron has been carried out at a power level of 4 kW. A rectangular laser beam of 1364 mm was used for hardening at scan speeds of 1000, 1500 and 2000 mm min 21 . The laser heat treated surfaces were characterised for their microstructure using optical and scanning electron microscopy which revealed different levels of martensitic transformation based on the scan speed employed in processing the samples. The microhardness profile of the heat treated region revealed much higher hardness values as compared with that of base metal. The wear resistance of the laser heat treated samples was evaluated in the pin on disc machine as per ASTM standard G-99A at a constant load of 10 kg and a sliding speed of 5 m s 21 . The results indicated highest wear resistance for sample processed at 1000 mm min 21 in the case of AISI 1018 steel, while in the case of AISI 4140 steel and cast iron, the sample processed at 2000 and 1500 mm min 21 exhibited the highest wear resistance in the range of test parameters employed. The wear scars after the test have been studied using scanning electron microscopy which revealed oxidative wear and microploughing of the surface under test conditions.

Fastin situphase and stress analysis during laser surface treatment: A synchrotron x-ray diffraction approach

“…It produces hard, wear resistant surface layers by means of a local heat treatment provoking a ferriteaustenite transformation followed by martensite formation. 1,2 The required local heating is accomplished by the use of high power laser radiation as energy source, while the subsequent rapid cooling is due to self-quenching of the material combined with controlled laser heating. Due to the interaction between the laser beam photons and the free electrons at the workpiece surface the laser beam is absorbed within an area, which lateral dimensions are limited by the laser beam cross section size.…”

Microstructure Formation and Fracturing Characteristics of Grey Cast Iron Repaired Using Laser

“…Some significant studies have been performed on improving surface properties of cast iron by laser surface modification. Laser hardening of grey cast iron was performed by Sridhar et al [ 9 ]. In his experiments, different microstructures of treated surface were derived with various scanning speed.…”

Influence Of Laser Hardening By Round, Profiled And Oscillating Beam On The Increase Of Service Life Of Machine Parts

“…The processing of AISI 1018, AISI 4140 steels and gray cast iron was carried out on a diode laser at a constant power of 4 kW. The beam had a rectangular profile measuring 13 × 4 mm [4]. The scanning speed varied from 1000 to 2000 mm/ min.…”

“…Обработку сталей AISI 1018, AISI 4140 и серого чугуна проводили на диодном лазере с постоянной мощностью 4 кВт. Луч имел прямоугольный профиль размером 13 × 4 мм [4]. Скорость сканирования варьировалась от 1 000 до 2 000 мм/мин.…”