Characteristics of laser assisted machining for silicon nitride ceramic according to machining parameters

Abstract

This paper describes the Laser Assisted Machining (LAM) that cuts and removes softened parts by locally heating the ceramic with laser. Silicon nitride ceramics can be machined with general machining tools as well, because YSiAlON, which was made up ceramics, is soften at about 1,000℃. In particular, the laser, which concentrates on highly dense energy, can locally heat materials and very effectively control the temperature of the heated part of specimen. Therefore, this paper intends to propose an efficient machining method of ceramic by deducing the machining governing factors of laser assisted machining and understanding its mechanism. While laser power is the machining factor that controls the temperature, the CBN cutting tool could cut the material more easily as the material gets deteriorated from the temperature increase by increasing the laser power, but excessive oxidation can negatively affect the quality of the material surface after machining. As the feed rate and cutting depth increase, the cutting force increases and tool lifespan decreases, but surface oxidation also decreases. In this experiment, the material can be cut to 3mm of cutting depth. And based on the results of the experiment, the laser assisted machining mechanism is clarified.

Laser Assisted Machining of Difficult to Cut Materials: Research Opportunities and Future Directions - A Comprehensive Review

“…The force ratio such as feed force/cutting force is found to decrease on zirconia [28] and mullite [29] resulted at higher Tmr which indicates the evidence of significant softening of the work piece near the cutting zone and quasi-plastic deformation. It is observed that cutting speed has the most significant influence on surface roughness followed by feed rate and depth cut [30].…”

“…The most common wear mechanism observed on laser assisted machining of zirconia with PCBN is abrasion, diffusion and adhesion [27]. But the abrasive and diffusive wear is not observed in LAM of silicon nitride [25,30] when compared to zirconia [27] due to low ductility and thermal diffusivity of zirconia. PCD is found to be not suitable for LAM on zirconia ceramics.…”

Microstructure and Mechanical Properties of Al2O3/Er3Al5O12 Binary Eutectic Ceramic Prepared by Bridgman Method

“…However, their mechanical properties above 1100 °C will be significantly degraded [1], and their high temperature stability and safety cannot meet the aviation needs. SiC/SiC [2], C/C [3,4] and Si 3 N 4 [5] non-oxide composites possess higher melting point, but they are easily oxidized in the ultra-high temperature air environment, or at least their anti-oxidation ability is far from meeting the needs of aero engines, which leads to the sharp deterioration of their mechanical properties.…”

Determination of the machining parameters of nickel-based alloys by High-Power diode laser

“…Therefore, the yield strength of the workpiece can be reduced by the preheating. [7][8][9][10] The method leads to about a 60-80% reduction in the processing cost. 8,11 The LAM process facilitates the more efficient machining of nickel-based superalloys, through for example, decreasing the cutting force and tool wear, reducing the occurrence of chattering and of catastrophic tool failure, and increasing the material removal rate (MRR).…”