Advanced Search
RSS LinkedIn Twitter

Journal Archive

Platinum Metals Rev., 2013, 57, (3), 177

doi:10.1595/147106713x668541

Crystallographic Properties of Osmium

Assessment of properties from absolute zero to 1300 K

SHARE THIS PAGE:

Article Synopsis

The crystallographic properties of osmium at temperatures from absolute zero to the experimental limit at 1300 K are assessed following a review of the literature published between 1935 and to date. Selected values of the thermal expansion coefficients and measurements of length changes due to thermal expansion have been used to calculate the variation with temperature of the lattice parameters, interatomic distances, atomic and molar volumes and densities. The data is presented in the form of Equations and Tables. The density of osmium at 293.15 K is 22,589 kg m3.

This is the seventh in a series of papers in this Journal on the crystallographic properties of the platinum group metals (pgms), following two papers on platinum (1, 2) and one each on rhodium (3), iridium (4), palladium (5) and ruthenium (6). Like ruthenium, osmium exists in a hexagonal close-packed (hcp) structure (Pearson symbol hP2) up to the melting point estimated by the present author to be 3400 ± 50 K (7) for the pure metal. The actual published values of 3318 ± 30 K by Knapton et al. (8) were for metal of only about 99.7% purity and of 3283 ± 10 K by Douglass and Adams (9) for metal of 99.5% purity.

The thermal expansion is represented by three sets of lattice parameter measurements: those of Owen and Roberts (10, 11) (from 293 K to 873 K) and Schröder et al. (12) (from 289 K to 1287 K) in the high-temperature region and those of Finkel’ et al. (13) (from 79 K to 300 K) in the low-temperature region. The latter measurements were only shown graphically and by incorrect equations with the actual data points as length change values being given by Touloukian et al. (14). As shown below the latter measurements are incompatible with the high-temperature data so the high- and low-temperature data were initially treated separately.

Thermal Expansion

High-Temperature Region

Length change values derived from the lattice parameter measurements of Owen and Roberts (10, 11) and Schröder et al. (12) agree satisfactorily and are represented by Equations (i) and (ii) for the a-axis and c-axis respectively. On the basis ± 100δL/L293.15 this leads to standard deviations of ± 0.004 and ± 0.002 respectively. The selected values were extended to a rounded temperature of 1300 K.

Low-Temperature Region

The measurements of Finkel’ et al. (13) as given by Touloukian et al. (14) (Figure 1) were fitted to smooth Equations (iii) and (iv). The incompatibility of these measurements with the high-temperature data can be shown by deriving thermal expansion coefficients from these equations at 293.15 K as αa = 5.8 × 106 K1 and αc = 8.8 × 106 K1. These values are notably higher than those calculated from Equations (i) and (ii) and as given in Tables I and II. In spite of the high purity claimed for the metal used in the experiments of Finkel’ et al., the c-axis lattice parameter value of 0.43174 nm at 293.15 K is notably lower than all other values given in Table III suggesting that these measurements must be treated with a certain degree of suspicion. Because it does not appear to be possible to reconcile the high- and low-temperature data the measurements of Finkel’ et al. were rejected.

Fig. 1.

Differences between the measurements of Finkel’ et al. (13) as given by Touloukian et al. (14) and the selected values

Differences between the measurements of Finkel’ et al. (13) as given by Touloukian et al. (14) and the selected values

 

Table I

Crystallographic Properties of Osmium

Temperature, KThermal expansion coefficient, αa, 106 K1Thermal expansion coefficient, αc, 106 K1Thermal expansion coefficient, αavr, 106 K1 aLength change, δa/a293.15 K× 100, % Length change, δc/c293.15 K × 100, % Length change, δavr/avr293.15 K × 100, %
0b 0 0 0 −0.100 −0.119 −0.106
10 0.035 0.035 0.035 −0.100 −0.119 −0.106
20 0.15 0.15 0.15 −0.100 −0.119 −0.106
30 0.49 0.51 0.49 −0.100 −0.118 −0.106
40 1.04 1.10 1.06 −0.099 −0.118 −0.105
50 1.62 1.78 1.70 −0.098 −0.116 −0.104
60 2.25 2.43 2.31 −0.096 −0.114 −0.102
70 2.72 2.97 2.81 −0.094 −0.111 −0.099
80 3.11 3.42 3.21 −0.090 −0.108 −0.096
90 3.41 3.79 3.54 −0.087 −0.104 −0.093
100 3.64 4.08 3.79 −0.084 −0.101 −0.089
110 3.82 4.31 3.98 −0.080 −0.096 −0.085
120 3.96 4.50 4.14 −0.076 −0.092 −0.081
130 4.07 4.67 4.27 −0.072 −0.087 −0.077
140 4.16 4.81 4.38 −0.068 −0.083 −0.073
150 4.24 4.93 4.47 −0.064 −0.078 −0.068
160 4.29 5.02 4.53 −0.059 −0.073 −0.064
170 4.33 5.10 4.59 −0.055 −0.068 −0.059
180 4.37 5.19 4.64 −0.051 −0.063 −0.055
190 4.41 5.26 4.69 −0.046 −0.057 −0.050
200 4.43 5.33 4.73 −0.042 −0.052 −0.045
210 4.45 5.40 4.76 −0.038 −0.047 −0.041
220 4.47 5.45 4.80 −0.033 −0.041 −0.036
230 4.49 5.51 4.83 −0.029 −0.036 −0.031
240 4.50 5.57 4.86 −0.024 −0.030 −0.026
250 4.52 5.63 4.89 −0.020 −0.025 −0.021
260 4.53 5.68 4.91 −0.015 −0.019 −0.016
270 4.54 5.73 4.94 −0.011 −0.013 −0.011
280 4.55 5.78 4.96 −0.006 −0.008 −0.007
290 4.56 5.83 4.98 −0.001 −0.002 −0.002
293.15 4.57 5.85 4.99 0 0 0
300 4.57 5.87 5.00 0.003 0.004 0.003
400 4.60 6.28 5.16 0.049 0.065 0.054
500 4.63 6.68 5.32 0.095 0.130 0.107
600 4.66 7.09 5.47 0.142 0.199 0.161
700 4.69 7.49 5.63 0.189 0.272 0.216
800 4.73 7.89 5.78 0.236 0.349 0.273
900 4.76 8.30 5.94 0.283 0.430 0.332
1000 4.79 8.70 6.09 0.331 0.516 0.393
1100 4.82 9.10 6.25 0.379 0.605 0.455
1200 4.85 9.49 6.40 0.428 0.699 0.518
1300 4.88 9.89 6.55 0.477 0.796 0.583

[i] a avr = average

[ii] b Since all values below 293.15 K are estimated they are given in italics

Table II

Further Crystallographic Properties of Osmium

Temperature, KLattice parameter, a, nma Lattice parameter, c, nmc/a ratioInteratomic distance, d1, nmAtomic volume, 103 nm3 Molar volume, 106 m3 mol−1 Density, kg m3
0b 0.27315 0.43148 1.5797 0.26723 13.939 8.395 22661
10 0.27315 0.43148 1.5797 0.26723 13.939 8.395 22661
20 0.27315 0.43148 1.5797 0.26723 13.940 8.395 22661
30 0.27315 0.43148 1.5797 0.26723 13.940 8.395 22661
40 0.27315 0.43148 1.5797 0.26723 13.940 8.395 22660
50 0.27315 0.43149 1.5797 0.26724 13.941 8.395 22659
60 0.27316 0.43150 1.5797 0.26724 13.941 8.396 22658
70 0.27316 0.43151 1.5797 0.26725 13.942 8.396 22656
80 0.27317 0.43152 1.5797 0.26726 13.944 8.397 22654
90 0.27318 0.43154 1.5797 0.26727 13.945 8.398 22652
100 0.27319 0.43156 1.5797 0.26728 13.947 8.399 22649
110 0.27320 0.43157 1.5797 0.26729 13.948 8.400 22647
120 0.27321 0.43159 1.5797 0.26731 13.950 8.401 22644
130 0.27322 0.43161 1.5797 0.26731 13.952 8.402 22641
140 0.27323 0.43163 1.5797 0.26732 13.954 8.403 22638
150 0.27325 0.43165 1.5797 0.26734 13.955 8.404 22635
160 0.27326 0.43168 1.5797 0.26735 13.957 8.405 22632
170 0.27327 0.43170 1.5797 0.26736 13.959 8.406 22629
180 0.27328 0.43172 1.5798 0.26738 13.961 8.408 22626
190 0.27329 0.43175 1.5798 0.26739 13.962 8.409 22623
200 0.27331 0.43176 1.5798 0.26740 13.965 8.410 22620
210 0.27332 0.43179 1.5798 0.26742 13.967 8.411 22616
220 0.27333 0.43181 1.5798 0.26743 13.969 8.412 22613
230 0.27334 0.43183 1.5798 0.26744 13.971 8.414 22610
240 0.27335 0.43186 1.5799 0.26746 13.973 8.415 22607
250 0.27337 0.43188 1.5799 0.26747 13.975 8.416 22603
260 0.27338 0.43191 1.5799 0.26748 13.977 8.417 22600
270 0.27339 0.43193 1.5799 0.26750 13.979 8.419 22596
280 0.27340 0.43196 1.5799 0.26751 13.981 8.420 22593
290 0.27341 0.43198 1.5799 0.26753 13.983 8.421 22590
293.15 0.27342 0.43199 1.5800 0.26753 13.984 8.421 22589
300 0.27343 0.43201 1.5800 0.26754 13.986 8.422 22586
400 0.27355 0.43227 1.5802 0.26769 14.007 8.435 22552
500 0.27368 0.43255 1.5805 0.26785 14.029 8.448 22517
600 0.27381 0.43285 1.5808 0.26801 14.052 8.462 22480
700 0.27394 0.43316 1.5813 0.26818 14.075 8.476 22443
800 0.27406 0.43350 1.5817 0.26836 14.099 8.491 22404
900 0.27419 0.43385 1.5823 0.26855 14.124 8.506 22365
1000 0.27433 0.43422 1.5829 0.26874 14.149 8.521 22325
1100 0.27446 0.43460 1.5835 0.26894 14.176 8.537 22284
1200 0.27459 0.43501 1.5842 0.26915 14.203 8.553 22241
1300 0.27472 0.43543 1.5850 0.26936 14.230 8.570 22198

[i] a a = d2

[ii] b Since all values below 293.15 K are estimated they are given in italics

Table III

Lattice Parameter Values at 293.15 Ka

Authors (Year)ReferenceOriginal temperature, KOriginal unitsLattice parameters, a, corrected to 293.15 K, nmLattice parameters, c, corrected to 293.15 K, nmNotes
Owen et al. (1935) (20) 291 kX 0.27361 0.43189 (a)
Owen and Roberts (1936) (10) 291 kX 0.27357 0.43191 (a)
Owen and Roberts (1937) (11) 293 kX 0.27355 0.43194 (a)
Finkel’ et al. (1971) (13) 293 Å 0.27346 0.43174 (a), (b)
Rudman (1965) (21) rtb Å 0.27341 0.43188 (c)
Swanson et al. (1955) (22) 299 Å 0.27342 0.43198
Mueller and Heaton (1961) (23) rt Å 0.27345 0.43200
Taylor et al. (1961, 1962) (24, 25) 296 Å 0.27342 0.43201
Schröder et al. (1972) (12) 289 Å 0.27340 0.43198

[i] a Selected values for the present paper 0.27342 ± 0.00002 and 0.43199 ± 0.00002

[ii] b rt = room temperature

[iii] Notes to Table III

(a) For information only – not included in the average

(b) Lattice parameter values given by Touloukian et al. (14)

(c) The c-axis value was not included in the average

In order to extrapolate below room temperature the procedure given in Appendix A was adopted. This utilises specific heat values selected by the present author (15) as expanded in Appendix C, leading to Equations (vii) and (viii) which were extrapolated in order to represent thermal expansion from 0 K to 293.15 K. Because there are two axes, the values of low-temperature specific heat as given in Appendix C can be substituted into the Equations, removing the need to develop a relatively large number of complimentary spline-fitted polynomial equations to correspond to Equations (vii) and (viii). On the basis of the expression:

100 × (δL/L293.15 K (experimental) − δL/L293.15 K (calculated))

where δL/L293.15 K (experimental) are the experimental length change values relative to 293.15 K as calculated from Equations (iii) and (iv) and δL/L293.15 K (calculated) are the relative length change values as given in Table I, the measurements of Finkel’ et al. for the a-axis over the range 80 K to 240 K show a bias of 0.005 to 0.006 lower than the selected values. For the c-axis at 80 K the difference is 0.029 lower with a trend to agree with the selected values with increasing temperature.

The Lattice Parameter at 293.15 K

The values of the lattice parameters, a and c, given in Table III represent a combination of those values selected by Donohue (16) and more recent measurements. Values originally given in kX units were converted to nanometres using the 2010 International Council for Science: Committee on Data for Science and Technology (CODATA) Fundamental Constants (17, 18) conversion factor for CuKα1, which is 0.100207697 ± 0.000000028. Values given in angstroms (Å) were converted using the default ratio 0.100207697/1.00202 where the latter value represents the old conversion factor from kX units to Å. Lattice parameter values were corrected to 293.15 K using the values of the thermal expansion coefficient selected in the present review. Density values given in Tables I and II were calculated using the currently accepted atomic weight of 190.23 ± 0.03 (19) and an Avogadro constant (NA) of (6.02214129 ± 0.00000027) × 1023 mol1 (17, 18). From the lattice parameter values at 293.15 K selected in Table III as: a = 0.27342 ± 0.00002 nm and c = 0.43199 ± 0.00002 nm, the derived selected density is 22,589 ± 5 kg m3 and the molar volume is (8.4214 ± 0.0013) × 106 m3 mol1. The difference from the density value for iridium, 22,562 ± 11 kg m3 (4), at 27 ± 12 kg m3 is considered to be the proof that osmium is the densest metal at room temperature and pressure.

In Tables I and II the interatomic distance d1 = (a2/3 + c2/4)½ and d2 = a. The atomic volume is (√3 a2 c)/4 and the molar volume is calculated as NA (√3 a2 c)/4, equivalent to atomic weight divided by density. Thermal expansion αavr = (2 αa + αc)/3 and length change δavr/avr293.15 K = (2 δa/a293.15 K + δc/c293.15 K)/3 (avr = average).

High-Temperature Thermal Expansion Equations for Osmium (293.15 K to 1300 K)

δa/a293.15 = −1.32379 × 103 + 4.46595 × 106 T + 1.69909 × 1010 T 2 (i)

δc/c293.15 = −1.53749 × 10−3 + 4.64427 × 10−6 T + 2.04826 × 10−9 T 2 (ii)

Equations Representing the Thermal Expansion Data of Finkel’ et al. (13) (79 K to 300 K)

δa/a293.15 = −1.22081 × 10−3 + 3.13600 × 10−6 T + 1.37670 × 10−9 T 2 + 7.27143 × 10−12 T 3 (iii)

δc/c293.15 = −1.71224 × 10−3 + 3.88446 × 10−6 T + 3.26721 × 10−9 T 2 + 1.16202 × 10−11 T 3 (iv)

αa (K−1) = Cp (−3.14503 × 10−8 + 6.95814 × 10−10 T + 1.86500 × 10−5 / T) (v)

αc (K−1) = Cp (−7.35814 × 10−8 + 1.16358 × 10−9 T + 2.62261 × 10−5 / T) (vi)

Low-Temperature Thermal Expansion Equations for Osmium (0 K to 293.15 K)

αa (K−1) = Cp (1.58546 × 10−7 + 1.09521 × 10−11 T + 6.88982 × 10−6 / T) (vii)

αc (K−1) = Cp (1.71988 × 10−7 + 1.41412 × 10−10 T + 6.95413 × 10−6 / T) (viii)

High-Temperature Specific Heat Equation (240 K to 3400 K)

Cp (J mol−1 K−1) = 26.1938 + 2.64636 × 10−4 T + 1.15788 × 10−6 T 2 + 1.599912 × 10−10 T 3 − 150378/T 2 (ix)

Summary

The number of measurements of the thermal expansion data for osmium is very limited and although the two high-temperature sets of lattice parameter measurements show satisfactory agreement, their usefulness only applies from room temperature to about 1300 K. The low-temperature lattice parameter measurements appear to be completely incompatible with the high-temperature data and were therefore rejected. Instead a novel approach was used to obtain values in the low-temperature region that agreed with the high-temperature data. Clearly the thermal expansion situation for osmium is unsatisfactory and new measurements are required at both low- and high-temperatures.

Appendix A

Representative Equations for Extrapolation Below 293.15 K

Equations (i) and (ii) are considered to be confined within the experimental limits of 289 K to 1287 K except for an extrapolation to a rounded maximum of 1300 K. Therefore in order to extrapolate beyond these limits a thermodynamic relationship is required such as that proposed by the present author to represent a correlation and interpolation of low-temperature thermal expansion data (1). In this case the relationship was evaluated in the high-temperature region and extrapolated to the low-temperature region. Equations (i) and (ii) were differentiated in order to obtain values of α*, the thermal expansion coefficient relative to 293.15 K, with thermodynamic thermal expansion coefficients calculated as α = α*/(1 + δL/L293.15 K). Selected values of α at 293.15 K and in the range 300 K to 700 K at 50 K intervals were then combined with high-temperature specific heat values calculated from Equation (ix) to derive Equations (vii) and (viii). These were then extrapolated to the low-temperature region using the specific heat values given in Appendix C. The range 293.15 K to 700 K was selected since this gave a satisfactory agreement between the derived experimental and calculated values. Length change values corresponding to Equations (vii) and (viii) were obtained by three-point integration.

Appendix B

The Quality of the Density Value for Osmium at 0 K

In view of the novel approach used to estimate the low-temperature properties and the relatively large extrapolation used, an independent estimate of the density at 0 K would be considered as a test of the quality of the procedure used. Such a value can be obtained from the rejected measurements of Finkel’ et al. (13) as given by Touloukian et al. (14). Equations (iii) and (iv) are considered as being confined within their experimental limits of 80 K to 293.15 K and therefore in order to extrapolate beyond these limits a similar approach to that used in Appendix A was applied. This approach led to Equations (v) and (vi) which are applicable between the limits 80 K to 293.15 K and these were extrapolated to 0 K using the specific heat values given in Appendix C. Three-point integration was used to derive values at 0 K of 100 δa/a293.15 = −0.107 and 100 δc/c293.15 = −0.153 so that the derived density value is thus 22,672 kg m−3 which is surprisingly only 11 kg m−3 (0.05%) greater than the selected value. It is possible therefore that the true density could lie between these two values although based on the selected value it is considered that the density at 0 K can best be represented as 22,661 ± 11 kg m−3.

Appendix C

Specific Heat Values for Osmium

Because of the large number of spline fitted equations that would be required to conform to both Equations (vii) and (viii), a different approach has been used for the non-cubic metals in that specific heat values are directly applied to these equations. However this would require that the table of low-temperature specific heat values originally given by the present author (15) has to be more comprehensive and the revised table is given as Table IV. In the high-temperature region Equation (ix) represents the specific heat essentially from 240 K to the melting point and is obtained by differentiating the selected enthalpy equation given by the present author (15). Selected values derived from Equation (ix) are given in Table V.

Table IV

Low-Temperature Specific Heat Values for Osmium

Temperature, KSpecific heat, J mol−1 KTemperature, KSpecific heat, J mol−1 KTemperature, KSpecific heat, J mol−1 K
10 0.0417 90 14.448 210 22.928
15 0.116 100 15.939 220 23.163
20 0.290 110 17.182 230 23.441
25 0.636 120 18.231 240 23.715
30 1.252 130 19.132 250 23.929
35 2.104 140 19.912 260 24.119
40 3.139 150 20.577 270 24.290
45 4.322 160 21.085 280 24.444
50 5.604 170 21.533 290 24.584
60 8.205 180 21.975 293.15 24.625
70 10.563 190 22.377 298.15 24.688
80 12.661 200 22.695 300 24.711
Table V

Selected High-temperature Specific Heat Values for Osmium

Temperature, KSpecific heat, J mol−1 KTemperature, KSpecific heat, J mol−1 KTemperature, KSpecific heat, J mol−1 K
293.15 24.625 500 26.034 800 26.994
298.15 24.688 550 26.219 900 27.301
300 24.711 600 26.386 1000 27.626
350 25.208 650 26.543 1100 27.975
400 25.555 700 26.694 1200 28.351
450 25.819 750 26.844 1300 28.757

BACK TO TOP

References

  1.  J. W. Arblaster, Platinum Metals Rev., 1997, 41, (1), 12 LINK https://www.technology.matthey.com/article/41/1/12-21/
  2.  J. W. Arblaster, Platinum Metals Rev., 2006, 50, (3), 118 LINK https://www.technology.matthey.com/article/50/3/118-119/
  3.  J. W. Arblaster, Platinum Metals Rev., 1997, 41, (4), 184 LINK https://www.technology.matthey.com/article/41/4/184-189/
  4.  J. W. Arblaster, Platinum Metals Rev., 2010, 54, (2), 93 LINK https://www.technology.matthey.com/article/54/2/93-102/
  5.  J. W. Arblaster, Platinum Metals Rev., 2012, 56, (3), 181 LINK https://www.technology.matthey.com/article/56/3/181-189/
  6.  J. W. Arblaster, Platinum Metals Rev., 2013, 57, (2), 127 LINK https://www.technology.matthey.com/article/57/2/127-136/
  7.  J. W. Arblaster, Platinum Metals Rev., 2005, 49, (4), 166 LINK https://www.technology.matthey.com/article/49/4/166-168/
  8.  A. G. Knapton, J. Savill and R. Siddall, J. Less Common Met., 1960, 2, (5), 357 LINK http://dx.doi.org/10.1016/0022-5088(60)90044-8
  9.  R. W. Douglass and E. F. Adkins, Trans. Met. Soc. AIME, 1961, 221, 248
  10.  E. A. Owen and E. W. Roberts, Philos. Mag., 1936, 22, (146), 290
  11.  E. A. Owen and E. W. Roberts, Z. Kristallogr., 1937, A96, 497
  12.  R. H. Schröder, N. Schmitz-Pranghe and R. Kohlhaas, Z. Metallkd., 1972, 63, (1), 12
  13.  V. A. Finkel', M. Palatnik and G. P. Kovtun, Fiz. Met. Metalloved., 1971, 32, (1), 212; translated into English in Phys. Met. Metallogr., 1972, 32, (1), 231
  14.  Y. S. Touloukian, R. K. Kirby, R. E. Taylor and P. D. Desai, “Thermal Expansion: Metallic Elements and Alloys”, Thermophysical Properties of Matter, The TPRC Data Series, Vol. 12, eds. Y. S. Touloukian and C. Y. Ho, IFI/Plenum Press, New York, USA, 1975
  15.  J. W. Arblaster, CALPHAD, 1995, 19, (3), 349 LINK http://dx.doi.org/10.1016/0364-5916(95)00032-A
  16.  J. Donohue, “The Structure of the Elements”, John Wiley and Sons, New York, USA, 1974
  17.  P. J. Mohr, B. N. Taylor and D. B. Newell, Rev. Mod. Phys., 2012, 84, (4), 1527 LINK http://dx.doi.org/10.1103/RevModPhys.84.1527
  18.  P. J. Mohr, B. N. Taylor and D. B. Newell, J. Phys. Chem. Ref. Data, 2012, 41, (4), 043109 LINK http://dx.doi.org/10.1063/1.4724320
  19.  M. E. Wieser and T. B. Coplen, Pure Appl. Chem., 2011, 83, (2), 359 LINK http://dx.doi.org/10.1351/PAC-REP-10-09-14
  20.  E. A. Owen, L. Pickup and I. O. Roberts, Z. Kristallogr., 1935, A91, 70
  21.  P. S. Rudman, J. Less Common Met., 1965, 9, (1), 77 LINK http://dx.doi.org/10.1016/0022-5088(65)90040-8
  22.  H. E. Swanson, R. K. Fuyat and G. M. Ugrinic, “Standard X-Ray Diffraction Powder Patterns”, NBS Circular Natl. Bur. Stand. Circ. (US) 539, 1955, 4, 8
  23.  M. H. Mueller and L. R. Heaton, “Determination of Lattice Parameters with the Aid of a Computer”, US Atomic Energy Commission, Argonne National Laboratory, Rep. ANL-6176, January 1961
  24.  A. Taylor, B. J. Kagle and N. J. Doyle, J. Less Common Met., 1961, 3, (4), 333 LINK http://dx.doi.org/10.1016/0022-5088(61)90025-X
  25.  A. Taylor, N. J. Doyle and B. J. Kagle, J. Less Common Met., 1962, 4, (5), 436 LINK http://dx.doi.org/10.1016/0022-5088(62)90028-0

The Author

John W. Arblaster is interested in the history of science and the evaluation of the thermodynamic and crystallographic properties of the elements. Now retired, he previously worked as a metallurgical chemist in a number of commercial laboratories and was involved in the analysis of a wide range of ferrous and non-ferrous alloys.

Read more from this issue »

BACK TO TOP

SHARE THIS PAGE: