Search results

The blocks were then homogeneized at 1050 °C for 36 h in order to insure chemical homogeneity and hot-rolled at 1050 °C using 5% reduction steps until a total reduction of 65%.
The EBSD data were acquired with an Oxford® HKL Channel 5 software package.
The data analyses were carried out by means of the Oxford® AZTEC software package.

This technique provides data on the viscosity response of the semisolid slurry under a rapid share change (i.e. a transient condition).
The normalized height reduction (h/h0, h = instantaneous height of billet and h0 = initial height of billet) as function of compression time is shown in Figure 5.
(a) (b) Fig. 5 Normalized height reductions (h/h0) of SEED processed 7075 slurries as a function of time under rapid compression for different temperatures.
The data are plotted in the transient state (less than 1 second) as the deformation was completed around 0.7 second.

Because it has good strength, plastic toughness and creep resistance at 650ºC~700ºC (typical room temperature performance data: tensile strength Around 1100MPa, the elongation can reach 8-14%[4]), and the density is low, so it has good application potential in the aviation and aerospace fields, but it is generally believed that the long-term stable working temperature of this material is difficult to reach 750ºC.
It is generally believed that its long-term use temperature can even reach 760°C~800°C(typical high temperature performance data: 800ºC, tensile The tensile strength is about 500MPa [5, 6]).
On the one hand, Ti2AlNb alloys and γ-TiAl intermetallic compounds can replace conventional Ti-based alloys, thereby increasing the service temperature of materials; on the other hand, they can also replace Ni-based superalloys to achieve weight reduction.
It can be seen that both Ti2AlNb alloy and γ-TiAl intermetallic compounds are new light-weight high-temperature structural materials with great application potential, which are of great significance for the further weight reduction of aerospace engines and the improvement of high-temperature service performance.

Introduction Recent years have seen a significant putsch toward the development of cost reduction technologies for the production of engineering components with titanium alloys [1, 2], particularly via the so called ‘near net shape’ forming routes.
These low level variations are considered to be signal noise associated with the raw voltage data and so are not considered to be indicative of any arc stability characteristics.
The data presented below shows that the hardness levels in the HAZ of PS samples differ significantly from that of both RHP and wrought materials.
Kraft, Summary of Emerging Titanium Cost Reduction Technologies, (EHK Technologies-for ORNL, Vancouver, WA, 2004), 1-59

The power consumption reduction rate is higher at lower I.S. speeds, S50C steel, which has a low recommended feed rate, was used as the work material, and X- and Y-axis cutting was performed using a square end mill.
The straight-line was defined as a point 0.25 mm from the surface and plotted, and the equation of the straight-line cut mark was calculated from the obtained coordinate data using the least-squares method. the standard deviation of the errors between the calculated straight-line equation and the coordinate data points was determined as the error in the straight-line portion.
[2] Bocken, N.M.P., Allwood, J.M., Willey, A.R., King, J.M.H., Development of an eco-ideation tool to identify stepwise greenhouse gas emissions reduction options for consumer goods, Journal of Cleaner Production, 19(12):1279-1287, (2011)

The fracture criteria applied was a reduction of frequency by 3 Hz.
Specimens that survived more than 107 cycles are considered as “run-outs”, and as expected, very big scattering in the fatigue test data is recorded for this heterogeneous material.
(a) (b) Figure 2: SN-curves for smooth and notched specimens in as-machined condition (a) and SN data for the notched specimen (b).
The microcracks observed in specimens with this condition, results in a reduction of loadbearing material, and not even this together with the rough surface can cause a decrease in fatigue strength of 15-20%.

Shrinkage behavior analysis of Alkali-Activated Concrete (AAC), without any external loading, is crucial to assess as there is limited data available.
A substantial amount of research has been done to understand the factors affecting the strength and mechanical properties of AAC [8-13]; however limited and conflicting data have been found towards understanding the cracking behavior of AAC.
Reduction of shrinkage strains from dry curing to seven days moist curing are as follows, 13% lower shrinkage strain in AAC-R1.5, almost 26% both in AAC-R1.0 and in OPCC.
Song, Assessment of CO 2 reduction of alkali-activated concrete, J.

Thus, optimal selection of cutting conditions still requires the expertise and experience of a skilled machinist or the information from a machining data handbook.
Considering our case, a reduction factor of 0.75 was implied, and we set the reference cutting force for our test to 525 N.
Similarly, NC codes were generated for 40 and 120 segments (data not presented here due to lack of space).
Table 2 Comparison of machining time before and after applying feed rate scheduling Machine time (s) Reduction (%) Without feed rate scheduling 20.5 Feed rate scheduling (20 segments) 15.8 22.9 Feed rate scheduling (30 segments) 14.3 30.2 Feed rate scheduling (40 segments) 10.7 47.8 Feed rate scheduling (60 segments) 10.0 51.2 Feed rate scheduling (120 segments) 9.2 55.1 (a) (b) Fig. 7 Machine time before and after implementing feed rate scheduling.

Summary of the experimental results Table 2 summarizes the main data and results obtained from the ten performed tests.
STEEL TAPE Effective area of one cord “3x2” Acord = 0.538 mm2 Ultimate tensile strength* fsu > 2800 MPa Modulus of elasticity* Es > 190000 MPa Ultimate tensile strain esu > 1.50% *Properties related to the dry sheet (Data provided by supplier) Low density (LD) GEOSTEEL G600 Medium density (MD) GEOSTEEL G2000 High density (HD) GEOSTEEL G3300 N. cord/mm r = 0.157 N. cord/mm r = 0.472 N. cord/mm r = 0.709 Weigth, w = 0.67 kg/m2 Weigth, w = 2.00 kg/m2 Weigth, w = 3.30 kg/m2 Equiv. thickness teq = Atref· r=0.084 mm Equiv. thickness teq = Atref· r= 0.254 mm Equiv. thickness teq = Atref· r = 0.381 mm Fig. 2.
Conversely, as expected, the application of an external strengthening works as an additional tensile reinforcement, thus causing a reduction of the beam’s deflection measured at the achievement of the peak force.
Such a reduction generally increases with the amount of the external strengthening and ranges from a minimum of 29% (see the test SRG-1LD) to a maximum value of 62% (see the test SRG-1LD-B).

According to official statistics of Ukrainian Foundation of social industrial accident and occupational diseases insurance, the data available by 30.12 2016 show that pneumoconiosis and dust bronchitis are rated the first in the structure of occupational diseases accounting for almost 70%.
At the same time, according to the data by the Ministry of Health of Ukraine, basic factors forming occupational pathology of dust etiology include: insufficient level of technologies and structural defects of machines and mechanisms (67%), lack of sanitation facilities or their defects (3%), non-use or improper use of individual protective devices (25%), violation of rules of safety regulations, modes of operation and rest, imperfection of working places (5%).
For instance, if workers do not use respirators for only 5 minutes during 480-minutes (8-hour) shift, then in terms of constant air dustiness being more than 100 MAC it is impossible to ensure its reduction within under-mask area down to the value being less than 1 MAC in terms of any respiratory efficiency during other 475 minutes.
To reduce the rate of occupational diseases it is necessary to concentrate efforts on: - reduction of air dustiness within breathing zone (advanced technology, automation, remote control, ventilation); - development of devices and methods that allow having better control of air dustiness within breathing zone; - improvement of quality and quantity of medical examinations for miners to detect occupational diseases in the initial stage as well as the increase in quality of preventive medical measures (phototherapy rooms etc.); - decrease in standards for safe use of of filter respirators in coal mines from 500 mg/m3 down to 100 mg/m3.