Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : heat treatment

Effect of Quenching Media on the Mechanical Properties and Abrasive Wear Resistance of (34Cr4) Steel Blade with Soil Texture Used in Agricultural Equipments

Abbas S. Alwan

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2205-2215

In this paper, a study the effect of quenching media on the mechanical properties and abrasive wear has been done on steel blade (34Cr4) for agriculture equipment with soil texture. It has found that heat treatment technique is promising to improve the quality of agriculture equipments and components working in soil under dry conditions. Abrasive wear resistance is very important in many applications and it is directly correlated with hardness of metal surface. The heat treatments have large role to alter the mechanical properties and wear resistance of steel type (34Cr4). It was found that the wear resistance increases with increase hardness which increases with varying quenching media as follows; 38HRC, 56.6 HRC, 58.3 HRC and 60.6 HRC for as – received sample, caustic Soda (10%), engine oil and flaxseed oil respectively. It was found also that the wear resistance increases with decreasing toughness to values 48.3 J, 45 J, 40.2 J and 27J respectively. Wear was presented on the worn surfaces of the steels which were used in this work. All mechanical properties depended on microstructure which consists of martensitic structure and some amount of carbide particles.

Effect of Heat Treatments on The Mechanical Properties And Wear Resistance of Al- Alloy Matrix Composite

Engineering and Technology Journal, 2011, Volume 29, Issue 12, Pages 518-533

Metal matrix composite (MMCs) of the base alloy (Al-0.978%Mg-1.03%Si) reinforced
with SiC particles (10 wt %) with particle size (53-106) μm was prepared by stir casting
using vortex technique. Solution heat treatment and aging are carried out at a constant
temperature of 175C° for different aging times. Many inspections and tests such as
microstructure, Vickers hardness and XRD analysis. Wear test type ( Pin – on – Disc) with
various applied loads and different exposure times at constant parameters was carried out
under dry sliding conditions.
It was found that the addition of SiC particles to base alloy improved the hardness and
wear resistance before and after heat treatment (precipitation hardening).
In addition, using SiC particles with alloy matrix resulted in a faster aging response i.e the
time of peak hardness decreased from 8hr to 5hr for base alloy and composite respectively.
These results indicate that the addition of SiC particles to Al –alloy matrix accelerates the
aging kinetic.

Effect of Heat Treatment on Fatigue Life of Aluminum Alloys 2024 And 7075

Ahmed. N. Al-Khazraji

Engineering and Technology Journal, 2010, Volume 28, Issue 22, Pages 6469-6481

This research studies the effect of heat treatment (precipitation hardening) on fatigue life of two aluminum alloys (2024) and (7075). The alloy (2024) is hardening by natural aging, while the artificial aging is used to hardening the alloy (7075). Mechanical tests are performed to determine the mechanical properties such as yield stress, ultimate tensile strength, hardness and endurance limit of the
alloys. The specimens which used in the tests are divided into eight groups according to the type of alloy, type of heat treatment, and shape. Notched and un-notched specimens are used to perform the tests. The fatigue tests are performed for different type of specimens.
The equations of fatigue life estimation are determined according to data which is obtained from the fatigue tests and endurance limit is calculated by using these equations for each type of specimens.

Effect of Heat Treatment on Notch Sensitivity Factor for Aluminum Alloys

Ahmed. N. Al-Khazraji; Emad Abdul Hussein Al-mudhafar

Engineering and Technology Journal, 2010, Volume 28, Issue 3, Pages 509-519

This study is concerned with the effect of heat treatment (precipitation
hardening) on notch sensitivity factor for aluminum alloy (7075). Tests were
conducted on four configurations of specimens, three of them which had external
circumferential notches with notch radii of 0.5 mm, 0.7 mm, and 1 mm. The
fourth configuration is un-notched specimens. The alloy samples which were used
in fatigue test were subjected to cold working before heat treatment. Dimensions
and roughness of the specimens were measured. The fatigue tests were performed
for different types of specimens. The (S-N) equation was derived for each group to
estimate the fatigue life under any applied stress amplitude. In addition, the
strength reduction factor (kf )and notch sensitivity factor (q) were calculated.
The results showed that the fatigue strength reduction factor were
increased after heat treatment and with decreasing notch radius. Also the notch
sensitivity factor increased with increasing notch radius and after heat treatment.
The enhancement percentage in notch sensitivity factor after the heat treatment for
1 mm radius notch was (22.616%).