Nyenyep Sriwardani
Universitas Sebelas Maret, Surakarta

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

PENGARUH UNSUR MAGNESIUM DAN HEAT TREATMENT PADA PERFORMA PISTON DARI VELG ALUMINIUM DENGAN ADC 12 Amin Hakim Nur Ulya; Budi Harjanto; Nyenyep Sriwardani
Nozel : Jurnal Pendididikan Teknik Mesin Vol 2, No 2 (2020)
Publisher : Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/nozel.v2i1.43229

Abstract

Aluminum alloy is one of the non ferrous metals that are widely used in various fields of life including one of the automotive industry. In Indonesia, the automotive industry is currently experiencing rapid development, as indicated by the number of motorized vehicles.there are many aluminium scrap from velg those are not used intensively, so casting is done through the use of aluminium velg. To prevent damage to the piston and to approach the standard, its hardness needs to be increased, namely by adding magnesium by 0.3% and 0.6% as well as artificial aging heat treatment method at a temperature of 155 ˚C with a variation of holding time used are 2 hours and 4 hours. The original piston has a hardness value 87.5 VHN. It turns out that aluminum velg material has a chemical composition of silicon element (Si) of 12.9% which is not in accordance with the A333.0 standard, so it is necessary to add the ADC 12 in casting to make new piston material. Based on the A333.0 standard, the suitable composition is 75% ADC 12 + 25% aluminum velg with a hardness value is 83.2 VHN, but still below from the original piston hardness. After the addition of magnesium and artificial aging the hardness of the new piston material has increased. The hardness of the material is 75% ADC 12 + 25% aluminum velg which has a hardness over the original piston is a material with artificial aging 4 hours with a hardness value is 87.6 VHN, material with the addition of magnesium elements 0.3% and 0.6% as well as artificial aging 4 hours which had a violence value are 88.6 VHN and 90.2 VHN. The process of adding magnesium and artificial aging also affects the metallography of the material, namely the structure and shape of the microstructure becomes more organized and there is a change in grain size.
PELAKSANAAN PRAKTIK KERJA INDUSTRI PADA PESERTA DIDIK KELAS XI DI SMK NEGERI 2 KARANGANYAR DENGAN MODEL KIRKPATRICK Ayu Nuvita Sari; Muhammad Akhyar; Nyenyep Sriwardani
Nozel : Jurnal Pendididikan Teknik Mesin Vol 2, No 2 (2020)
Publisher : Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/nozel.v2i1.43231

Abstract

This study aims at: (1) obtaining a description the quality of implementation Internship Program Competency Ototronic Engineering class XI in SMK Negeri 2 Karanganyar in terms of the Reaction component; (2 obtaining a description the quality of implementation Internship Program Competency Ototronic Engineering class XI in SMK Negeri 2 Karanganyar in terms of the Learning component; (3) obtaining a description the quality of implementation Internship Program Competency Ototronic Engineering class XI in SMK Negeri 2 Karanganyar in terms of the Behavior component.This research was conducted at SMK Negeri 2 Karanganyar. This study was included in the type of evaluative research (evaluation research) where the evaluation model used was Kirkpatrick's evaluation model. The population in the study were students of SMK Negeri 2 Karanganyar at the Ototronic Engineering Expertise Program and the supervisor of the school in the ototronic engineering expertise program and supervisors in the industry who directly assisted the implementation of industrial work practices. The number of respondents was 108 students, 5 mentors for the ototronic engineering expertise program, and 5 mentors in the industry. Data collection techniques in this study used a questionnaire method that was distributed to students, an interview method with some student respondents, and all school supervisors and industry teachers, and documentation of the final score of Internship. Validity uses fact finding, namely the validity of logic. Therefore, fact finding for reliability testing is not necessary. Score analysis uses average analysis which will be assessed based on research criteria. The results of the study show: (1) aspects of reaction with student respondents who have an average value of 3.88 which includes very high criteria, this is indicated by the results on the indicators giving direction of 3.99; (2) aspects of evaluating learning with student respondents who have an average value of 3.82 which includes very high criteria, this is intended with the results on the discipline indicator of 4.00; (3) aspects of behavior evaluation with student respondents who have an average value of 4.07 which includes very high criteria, this is indicated by the results on the skills indicator after the internship is 4.25; (4) from the results of research conducted to obtaining a comprehensive picture when viewed from the components of reaction, learning, and behavior is very high including very high criteria.