Effect of laser radiation on the mechanical strength of a block of polymethyl methacrylate

1973 ◽  
Vol 7 (2) ◽  
pp. 208-211
Author(s):  
N. P. Novikov ◽  
S. S. Salu�n'ya
Keyword(s):  
Laser Radiation ◽  
Mechanical Strength ◽  
Polymethyl Methacrylate

Optically Transparent Polymethyl Methacrylate Composites made with Glass Fibers of Varying Refractive Index

1997 ◽  
Vol 12 (4) ◽  
pp. 1091-1101 ◽  
Author(s):  
Seunggu Kang ◽  
Hongy Lin ◽  
Delbert E. Day ◽  
James O. Stoffer
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Refractive Index ◽  
Mechanical Strength ◽  
Glass Fiber ◽  
Polymethyl Methacrylate ◽  
Optical Transmission ◽  
Annealing Temperature ◽  
Glass Fibers ◽  
Optically Transparent

The dependence of the optical and mechanical properties of optically transparent polymethyl methacrylate (PMMA) composites on the annealing temperature of BK10 glass fibers was investigated. Annealing was used to modify the refractive index (R.I.) of the glass fiber so that it would more closely match that of PMMA. Annealing increased the refractive index of the fibers and narrowed the distribution of refractive index of the fibers, but lowered their mechanical strength so the mechanical properties of composites reinforced with annealed fibers were not as good as for composites containing as-pulled (chilled) glass fibers. The refractive index of as-pulled 17.1 μm diameter fibers (R.I. = 1.4907) increased to 1.4918 and 1.4948 after annealing at 350 °C to 500 °C for 1 h or 0.5 h, respectively. The refractive index of glass fibers annealed at 400 °C/1 h best matched that of PMMA at 589.3 nm and 25 °C, so the composite reinforced with those fibers had the highest optical transmission. Because annealed glass fibers had a more uniform refractive index than unannealed fibers, the composites made with annealed fibers had a higher optical transmission. The mechanical strength of annealed fiber/PMMA composites decreased as the fiber annealing temperature increased. A composite containing fibers annealed at 450 °C/1 h had a tensile strength 26% lower than that of a composite made with as-pulled fibers, but 73% higher than that for unreinforced PMMA. This decrease was avoided by treating annealed fibers with HF. Composites made with annealed and HF (10 vol. %)-treated (for 30 s) glass fibers had a tensile strength (∼200 MPa) equivalent to that of the composites made with as-pulled fibers. However, as the treatment time in HF increased, the tensile strength of the composites decreased because of a significant reduction in diameter of the glass fiber which reduced the volume percent fiber in the composite.

Photoablation Studies of Polymers, Quartz, and Semiconductors with Vacuum Ultraviolet Laser Radiation

1991 ◽  
Vol 236 ◽  
Author(s):  
Peter R. Herman ◽  
Boyi Chen ◽  
David J. Moore ◽  
Mark Canaga-Retnam
Keyword(s):  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
Thermal Damage ◽  
Vacuum Ultraviolet ◽  
Medical Industry ◽  
Surface Melting ◽  
Excimer Lasers ◽  
Ultraviolet Laser ◽  
Low Threshold ◽  
Microelectronics Industry

AbstractExcimer lasers sources of 193nm and 157 nm wavelength were used to obtain new photoablation etching rates for several materials of interest to the microelectronics industry. The harder 157nm radiation provided lower ablation rates and smaller threshold fluences for Polyimide and Polymethyl Methacrylate (PMMA) than with 193nm. For normally robust materials like quartz and Teflon (PTFE), the 157nm laser produced clean and smooth ablation sites with low threshold fluences of 620mJ/cm2 and 68mJ/cm2, respectively, features impossible to obtain with conventional excimer lasers at longer wavelengths. The data should help define new micromachining applications of these two materials for the electronic, optical or medical industry. Results are also reported for GaAs and InP based materials which are found to undergo moderate etch rates of 30-80nm/pulse at fluences of ∼3J/cm2, but suffer thermal damage and material segregation due to surface melting.

Ultrafast Imaging of Ultraviolet Laser Ablation and Etching of Polymethyl Methacrylate

1989 ◽  
Vol 158 ◽  
Author(s):  
Bodil Braren ◽  
R. Srinivasan ◽  
Kelly G. Casey ◽  
Mildred Yeh
Keyword(s):  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
Initial Velocity ◽  
Average Velocity ◽  
Solid Material ◽  
Low Molecular Weight ◽  
Molecular Weight Polymer ◽  
Ultrafast Imaging ◽  
Visible Laser ◽  
Modification Of The Surface

ABSTRACTAblation and etching of the surface of polymethyl methacrylate (=PMMA) by pulses of 248 nm laser radiation ∼20 ns full width at half maximum (FWHM) have been probed by pulses of visible laser radiation (596 nm; < 1 ns FWHM). The results were recorded photographically in real time with a set time delay between the 248 nm ablation pulse and the 596 nm probe pulse. Modification of the surface structure of the polymer at a fluence ∼ 3 J/cm2 is first visible at 12 ns and appears to be complete in ∼ 60 ns. The first manifestation of the ablation does not occur until the UV pulse is over and consists of a nearly transparent shock-wave that has an initial velocity of 6 ∼ 104 cm/sec. Solid material from the ablated zone begins to leave the surface at ∼150 - 200 ns and reaches a maximum in intensity at 6 µs, continuing for ∼ 20 µs. The average velocity of the solid material, which is probably a low molecular weight polymer of PMMA, is 1.5 ∼ 104 cm/sec. The conclusion to be drawn from the present work is that the signal measured by photoacoustic detectors does not coincide with the bulk of the material leaving the surface.

Study of mechanical properties of aluminum, AMg6M alloy, and polymethyl methacrylate at high strain rates under the action of picosecond laser radiation

2012 ◽  
Vol 57 (2) ◽  
pp. 64-66 ◽  
Author(s):  
S. A. Abrosimov ◽  
A. P. Bazhulin ◽  
V. V. Voronov ◽  
I. K. Krasyuk ◽  
P. P. Pashinin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
High Strain ◽  
Picosecond Laser ◽  
Strain Rates ◽  
High Strain Rates

Features of the Polymethyl Methacrylate Destruction Process by Various Types of Dynamic Loading

2021 ◽  
Vol 899 ◽  
pp. 473-478
Author(s):  
B.I. Kunizhev ◽  
A.M. Kugotova ◽  
Z.S. Torshhoeva ◽  
Ruslan A. Shetov
Keyword(s):  
Comparative Analysis ◽  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
Dynamic Loading ◽  
High Speed ◽  
Laser Action ◽  
Initial Energy ◽  
Destruction Process ◽  
Energy Characteristics ◽  
Similarities And Differences

The paper presents a comparative analysis of the dynamic loading of a polymethyl methacrylate (PMMA) target by a polyethylene (PE) projectile exposed to laser radiation with similar initial energy characteristics of the projectile and the laser pulse. The similarities and differences in the mechanisms of the target's response and its destruction to high-speed mechanical and laser action are shown. A higher efficiency of laser irradiation in the destruction of PMMA was found, and the conditions for the transition of the fracture mechanism from brittle to elastic-plastic were shown.

An Investigation of the Effect of Laser Radiation on the Dielectric Parameters of Polymethyl Methacrylate

2018 ◽  
Vol 45 (5) ◽  
pp. 205-207
Author(s):  
Z.S. Torshkhoeva ◽  
A.S. Akhriev ◽  
B.I. Kunizhev
Keyword(s):  
Laser Radiation ◽  
Dielectric Loss ◽  
Dielectric Permittivity ◽  
Laser Pulse ◽  
Polymethyl Methacrylate ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Pulse Treatment ◽  
Dielectric Parameters ◽  
Temperature Range

The effect of laser radiation on the dielectric parameters of polymethyl methacrylate at a frequency of 50 kHz in the 170–420 K temperature range was investigated. It was shown that the laser pulse treatment of specimens leads to considerable changes in their dielectric permittivity and dielectric loss tangent.

Effect of continuous gas-laser radiation on polymethyl methacrylate

1972 ◽  
Vol 4 (2) ◽  
pp. 217-223
Author(s):  
D. P. Krindach ◽  
N. P. Novikov ◽  
Yu. I. Yudin
Keyword(s):  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
Gas Laser
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