The purpose of the present experiment was to obtain a good fusion zone between insert and aluminium alloy castings by the surface treatment of the insert.
The experiments were made on the alloys subjected to three kinds of treatments, which had given relatively good results in the pre-experiments; copper plating, nickel plating, aluminizing treatment, and no treatment for comparison.
Besides the above treatments, preheating was conducted to make the fusion easily on the insert and heat treatment was made for diffusion. Flux was used for removing oxide film.
The following results were obtained.
1) Good fusion zone was not obtained by casting with electroplated insert and preheated metallic mold.
2) The adhesion of the insert on the alloys was not improved by heat treatment after casting.
3) Good adherent surface was obtained by casting after the treatment of nickel plating on soft steel (S 20 C) bar and then dipping it in the flux consisting of 60% ZnCl₂ and 40% NaCl.
4) Mechanical strength was improved by designing the shapes of inserts.

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It was found by X-ray analysis that the crystals of flame-sprayed Al₂O₃ films were mainly composed of γ-form and partly of α-form.
The results obtained, by the two methods, powder process and rod process, agreed with each other.
The crystal structure was converted from γ-form into α-form by keeping the films for 2hr. at 1250°C.
The above conversion was more feasible in the sprayed films by rod process than in those by powder process.

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In machine tool, the accuracy of slideway is one of the important subjects as well as the stability of the rotation of main spindle.
Therefore, the slideways are protected from wear by means of lubricating oil and dust wiper, etc. In actual operations, however, accidents are apt to happen caused by the wear of slideways.
The actual lubricating conditions were analyzed on machine tool, especially on lathe, and the actual value of ZV/P indicating the lubricating conditions was obtained; in addition, critical value of ZV/P indicating the boundary point between fluid and boundary lubricating zones was also obtained.
Then, the experiments on the wear test of slideways with lathe were conducted under the actual lubricating conditions. The degree of wear of slideways was traced by checking the surface roughness with Talysurf roughness tester.
In this paper, there are described on the actual value of ZV/P on machine tool slideways, critical value of ZV/P, and the effects of lubricating conditions and the wiper on the wear of slideways are described.

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It is well known that the hardness of non-electrolytically plated Ni-P deposits may be so varied by heat-treatments that it is very high when treated at a suitable temperature. However, the hardness at high temperatures has never been measured.
In these experiments, the hardness at each high temperature during heating or cooling was measured with Micro Vickers Hardness Tester for high temperatures. The material used for substrate was steel of 0.5% C. As the results, maximum points of hardness were confirmed at 250 and 400°C. When the deposits, treated at above 400°C, were reheated, they showed a tendency to softening; while those, treated at lower temperatures, showed rehardening at about 400°C when they were reheated.
The samples of deposits were always more than 8μ in thickness as the results of preliminary investigation of the relation between depositing conditions and thickness or hardness.
Composition of the bath in these experiments was as follows:
NiCl₂⋅6H₂O 30g/l
NaH₂PO₂⋅H₂O 10g/l
Na₃C₆H₅O₇⋅2H₂O 15g/l
NaC₂H₃O₂⋅3H₂O 5g/l

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When the following pretreatments are applied in ABS resin, electroless copper having good adhesive property can be obtained as an undercoating for electroplating.
Chemical roughing CrO₃ 33g/l, conc. H₂SO₄ 800cc/l, 60-70°C, 1min↓Water rinsing Neutralization 10% NaOH, room temp.↓Water rinsing Sensitizing SnCl₂⋅2H₂O 40g/l, conc. HCl 70cc/l, room temp. 1min↓Water rinsing Activating AgNO₃ 1.5g/l, conc. NH₄OH 1.2cc/l, room Temp., 1min↓No rinsing↓Reducing 10% (vol.), formalin solution, room temp., a few sec.↓Drying 60-70°C↓No rinsing Electroless copper
When such pretreatments are applied, costly mechanical roughing process can be omitted and noble metals for activation are not needed, further more, the quality is far superior to the ones which are treated for activation with noble metals such as Pd or Au.

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